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Opinion Paper
Damien Gatinel

Challenging the “No Rub, No Cone” Keratoconus Conjecture

[Year:2018] [Month:January-June] [Volumn:7 ] [Number:1] [Pages:89] [Pages No:66-81][No of Hits : 1719]


ABSTRACT

Eye rubbing has long been acknowledged as a risk factor for keratoconus (KC), but its role in the pathogenesis of KC may not have been accorded sufficient prominence. This article puts forth the conjecture that KC is not a dystrophy of unknown genetics and biomolecular substratum, but rather a syndrome caused by eye rubbing, i.e., what has been called “keratoconus” is the direct consequence of mechanical trauma to the cornea by chronic and incessant eye rubbing, resulting in the progressive deformation and thinning of the corneal wall, the hallmarks of the disease. The conjecture is challenged in this article to investigate its compatibility with what is currently known about KC. The conjecture does not contradict previous clinical or experimental findings about KC, all of which can be interpreted in light of this proposed mechanism. Rather, it is a synthetic approach that incorporates the results of previous genetic and biochemical perspectives for understanding the pathophysiology of KC. In fact, this mechanical disease proposition would appear more compatible with explaining the variability of KC expression between patients, between eyes, and the predominance of sporadic cases. As such, eye rubbing may not be solely a risk factor as often coined in medical literature, but the direct cause of the syndrome labeled “keratoconus.” In conclusion, this mechanical theory provides a better explanatory framework for what is currently known about KC and confirms the validity of the “no rub, no cone” conjecture.

Keywords: Ectasia, Eye rubbing, Keratoconus.

How to cite this article: Gatinel D. Challenging the “No Rub, No Cone” Keratoconus Conjecture. Int J Kerat Ect Cor Dis 2018;7(1):66-81.

Source of support: Nil

Conflict of interest: None


 
Review Article
Damien Gatinel

Reevaluating the Effectiveness of Corneal Collagen Cross-linking and Its True Biomechanical Effect in Human Eyes

[Year:2017] [Month:January-June] [Volumn:6 ] [Number:1] [Pages:44] [Pages No:34-41][No of Hits : 3052]


ABSTRACT

The induction of cross-links in corneal tissue appears to be a promising technique to increase its stiffness and this has been the basis of treatment of keratoconus (KC) and corneal ectatic disease. However, there exists a striking discrepancy between the reported biomechanical effects of corneal collagen cross-linking (CXL) in vitro compared to in vivo, and this has not received much attention in the literature.
Despite the documentation of an increase in corneal stiffness in vitro by many investigators, reports that provide evidence of measurable and consistent biomechanical changes in corneal rigidity in vivo after CXL are lacking. Indeed, the absence of documented in vivo biomechanical improvement in CXL-treated corneas is a conundrum, which needs to be further explored. To explain this discrepancy, it has been postulated that biomechanical changes induced by CXL are too subtle to be measured by currently available diagnostic tools or have characteristics not discernible by these technologies. However, the dynamic bidirectional applanation device (Ocular Response Analyzer) and dynamic Scheimpflug analyzer instruments (Corvis ST) have demonstrated the ability to quantify even subtle biomechanical differences in untreated KC corneas of different ectatic degree, and document the reduction in corneal hysteresis (CH) and corneal resistance factor (CRF) in situations where the corneal stiffness is reduced, such as after laser in situ keratomileusis and surface ablation procedures. It has also been possible to demonstrate an altered CH and CRF in patients with diabetes, smoking habit, glaucoma, Fuchs’ dystrophy, and corneal edema. It is puzzling that these diagnostic tools could document subtle biomechanical changes in these situations, yet fail to measure the purported changes induced by CXL on corneas with progressive KC. This failure to document significant and consistent biomechanical changes in corneal rigidity could suggest that CXL does not induce a simple reversal of the particular biomechanical deficits that characterize KC, or make the cornea significantly more resistant to bending forces as has been widely postulated. The absence of measurable biomechanical change in living KC corneas after CXL could be a consequence of biomechanical strengthening which is insignificant compared to the marked weakening caused by preexisting alteration of the collagen structure, disorganization of collagen fiber intertwining, and compromised structural-mechanical homogeneity that are hallmarks of keratoconic disease, especially in corneas with progressive KC.
The changes in the cornea induced by CXL that have been described in vivo may instead be driven by a wound healing process in response to the removal of the corneal epithelial layer and subsequent exposure to riboflavin and ultraviolet-A (UVA). This paper will present evidence that sustains this hypothesis.

Keywords: Corneal biomechanics, Corneal epithelium, Crosslinking, Ectasia, Hysteresis, Keratoconus.

How to cite this article: Gatinel D. Reevaluating the Effectiveness of Corneal Collagen Cross-linking and Its True Biomechanical Effect in Human Eyes. Int J Kerat Ect Cor Dis 2017;6(1):34-41.

Source of support: Nil

Conflict of interest: None


 
Original Article
Michael W Belin, Jay J Meyer, Josh K Duncan, Rachel Gelman, Mark Borgstrom, Renato Ambrósio Jr

Assessing Progression of Keratoconus and Cross-linking Efficacy: The Belin ABCD Progression Display

[Year:2017] [Month:January-June] [Volumn:6 ] [Number:1] [Pages:44] [Pages No:1-10][No of Hits : 1312]


ABSTRACT

Several methods have been described to both evaluate and document progression in keratoconus and to show efficacy of cross-linking, however, there are no consistent generally accepted parameters. Modern corneal tomography, including both anterior and posterior elevation and pachymetric data can be used to screen for ectatic progression, be employed to detect earlier change and additionally to show efficacy of new treatment modalities, such as crosslinking.
To describe specific quantitative values that can be used as progression and efficacy determinants, the normal noise measurements of the three parameters used in the ABCD keratoconus classification (corneal thickness at the thinnest point, anterior and posterior radius of curvature taken from the 3.0 mm optical zone centered on the thinnest point), were determined. Values were obtained from both a normal population and a known keratoconic population. The 80 and 95% one-sided confidence intervals for all three parameters were surprisingly small, suggesting that they may perform well as progression and efficacy determinants.

Keywords: Collagen cross-linking, Ectatic disease, Keratoconus, Tomography, Topography.

How to cite this article: B elin M W, M eyer J J, D uncan J K, Gelman R, Borgstrom M, Ambrósio Jr R. Assessing Progression of Keratoconus and Cross-linking Efficacy: The Belin ABCD Progression Display. Int J Kerat Ect Cor Dis 2017;6(1):1-10.

Source of support: Nil

Conflict of interest: None


 
Original Article
SI Anisimov, SYAnisimova, AS Mistryukov, NS Anisimova

Technology of the Local Cross-linking (Part 1): Keratotensotopography and Vacuum-compression Topographic Test—New Diagnostic Possibilities for Studying the Local Biomechanical Properties of Cornea

[Year:2017] [Month:January-June] [Volumn:6 ] [Number:1] [Pages:44] [Pages No:14-16][No of Hits : 1231]


ABSTRACT

Aim: The aim of this study is the development and evaluation of clinical significance methodology for determining mechanical stress (MS) and elasticity of the cornea comparable to its topographic settings.

Materials and methods: Combining the data of optical pachymeter, keratotopography, and pneumotonometry through our special software allows us to get Lokolink MS distribution in the cornea in the form of maps, which we propose to call keratotensotopogram (KTT).

Results: Normal KTT has the form of concentric, uniform, and symmetrical zones. In keratoconus (KC), the corneal center is more tense than peripheral part of cornea. The focus zone of KC may coincide with the region of maximum MS or may be out of this area. In the process of vacuum-compression test, the reaction of profile of the cornea was markedly different in patients with healthy corneas and in patients with KC. In all cases of healthy cornea, the curvature increased in the center. In KC, the cornea became more flat in the center under high intraocular pressure (in 100% of cases).

Conclusion: The KTT ineyes with the cornea without pathology differs from KTT in the different cases of KC. The KTT can be used for the diagnosis and prediction of cornea’s state to perform the plan of UV irradiation areas for corneal collagen cross-linking.

Keywords: Corneal collagen cross-linking, Corneal topography, Keratotensotopogram, Vacuum-compression test.

How to cite this article: Anisimov SI, Anisimova SY, Mistryukov AS, Anisimova NS. Technology of the Local Cross-linking (Part 1): Keratotensotopography and Vacuumcompression Topographic Test—New Diagnostic Possibilities for Studying the Local Biomechanical Properties of Cornea. Int J Kerat Ect Cor Dis 2017;6(1):14-16.

Source of support: Nil

Conflict of interest: None


 
Case Series
Jorge S Haddad, Eliza Barnwell, Karolinne M Rocha, George O Waring IV, Renato Ambrosio Jr

First Clinical Impressions on the Integrated Corneal Tomography and Corneal Deformation with Scheimpflug Imaging

[Year:2017] [Month:July-December] [Volumn:6 ] [Number:2] [Pages:64] [Pages No:101-109][No of Hits : 915]


ABSTRACT

The purpose of this study is to report the preliminary findings and the retrospective clinical impressions of the integrated corneal tomography and corneal deformation parameters with a dynamic ultra-high-speed Scheimpflug camera equipped with a noncontact tonometer. Twelve eyes of six patients were evaluated by the Scheimpflug imaging system of the Pentacam HR and Corvis ST (OCULUS Optikgeräte GmbH, Wetzlar, Germany) devices. The parameters used were the Belin/Ambrósio deviation (BAD-D) and Corvis biomechanical index (CBI), as well as the recently published tomographic and biomechanical index (TBI), combined with a detailed clinical data and evaluation of normal eyes and patients with different stages of corneal ectasia.

Keywords: Case series, Corneal diseases, Corneal topography, Ectasia/diagnosis, Keratoconus, Tomography.

How to cite this article: Haddad JS, Barnwell E, Rocha KM, Waring IV GO, Ambrosio Jr R. First Clinical Impressions on the Integrated Corneal Tomography and Corneal Deformation with Scheimpflug Imaging. Int J Kerat Ect Cor Dis 2017;6(2):101-109.

Source of support: Nil

Conflict of interest: None


 
Review Article
Abdelsattar N Farrag, Ahmed A Hussein, Shiji Ummar

Treatment of Pellucid Marginal Degeneration

[Year:2017] [Month:July-December] [Volumn:6 ] [Number:2] [Pages:64] [Pages No:87-91][No of Hits : 780]


ABSTRACT

Purpose: To summarize the recent trends in the treatment of pellucid marginal degeneration (PMD) based on available published data.

Method and literature search: A PubMed search was conducted with combinations not limited to the following search terms: Pellucid marginal degeneration, Corneal ectasia, Corneal collagen cross-linking (CXL), Intracorneal ring segments (ICRS), Contact lens, Keratoplasty in corneal ectasia. A review of the search results was performed and relevant articles to the topic were included.

Summary: Ophthalmologists have got a wide array of therapeutic modalities for the management of PMD. However, the key to optimal treatment is careful clinical assessment of patients and their visual requirements and tailoring the treatment to individual patients.

Keywords: Corneal collagen cross-linking, Corneal ectasia, Intracorneal ring segment, Keratoplasty, Pellucid marginal degeneration.

How to cite this article: Farrag AN, Hussein AA, Ummar S. Treatment of Pellucid Marginal Degeneration. Int J Kerat Ect Cor Dis 2017;6(2):87-91.

Source of support: Nil

Conflict of interest: None


 
Research Article
Victor Penner, Kylee Lewis, Guillermo Rocha

Reduced High-order Aberrations using Wavefront-guided Partial Photorefractive Keratectomy and Accelerated Epithelium-off Corneal Cross-linking for Keratoconus

[Year:2017] [Month:July-December] [Volumn:6 ] [Number:2] [Pages:64] [Pages No:73-77][No of Hits : 703]


ABSTRACT

Purpose: To demonstrate clinical outcomes of epithelium-off corneal cross-linking (CXL) in combination with wavefrontguided photorefractive keratectomy (PRK) for the treatment of keratoconuns.

Materials and methods: Total, 28 keratoconic eyes of 21 patients were included. The Sirius Wavefront Analyzer (SCHWIND eye-tech-solutions GmbH and Co. KG) was used to evaluate the high-order aberrations (HOAs). The coupled Amaris 750S excimer laser then performed a PRK of no more than 40 μm using the measured HOA. The CXL was then carried out respecting the standard of 400 μm of corneal thickness.

Results: The average age was 32 (15-48) years. Uncorrected distance visual acuity (UDVA) improved from 0.58 to 0.31 logMAR (p < 0.001), with best corrected distance visual acuity (CDVA) improving from 0.03 to 0.02 logMAR (p = 0.7).
On manifest refraction, the average spherical component decreased from —1.87 to —1.40 D (0.47 ± 2.12, p = 0.4). Cylinder decreased from 2.18 to 0.87 D (1.31 ± 1.14 D, p < 0.001).
All HOAs decreased: total HO 0.94 to 0.58 (0.36 ± 0.42, p = 0.05); spherical aberration: 0.142 to —0.018 (0.160 ± 0.160, p < 0.001); secondary astigmatism: 0.21 to 0.11 (0.10 ± 0.11, p = 0.02); coma: 0.80 to 0.42 (0.38 ± 0.47, p = 0.03); trefoil: 0.33 to 0.29 (0.04 ± 0.17, p = 0.7).

Conclusion: Utilizing HOA to guide the laser treatment in combination with CXL resulted in a significant decrease of HOA at 6 months postprocedure. This is a small case series, but demonstrates a promising trend of improved HOA. Considering that keratoconic eyes have very irregular surfaces with significant HOA, reducing these aberrations should improve best corrected quality of vision. Having longer follow-up and greater numbers may demonstrate a clearer improvement.

Keywords: Cornea, Ectasia, High-order aberrations, Keratoconus, Photorefractive keratectomy, Spherical aberrations, Trefoil.

How to cite this article: Penner V, Lewis K, Rocha G. Reduced High-order Aberrations using Wavefront-guided Partial Photorefractive Keratectomy and Accelerated Epithelium-off Corneal Cross-linking for Keratoconus. Int J Kerat Ect Cor Dis 2017;6(2):73-77.

Source of support: Nil

Conflict of interest: None


 
Original Article
Renato Ambrósio Jr, Michael W Belin

Enhanced Screening for Ectasia Risk prior to Laser Vision Correction

[Year:2017] [Month:January-June] [Volumn:6 ] [Number:1] [Pages:44] [Pages No:23-33][No of Hits : 669]


ABSTRACT

Aim: To prospectively review current understanding and future trends of screening for keratectasia risk prior refractive laser vision correction (LVC).

Background: Progressive keratectasia is an uncommon but severe complication of LVC. Preoperative ectatic corneal disease is the most important risk factor. Screening for subclinical ectasia relies on proper interpretation of advanced diagnostic technologies, including front surface corneal topography, three-dimensional tomography, and biomechanical assessments.

Summary: Studies involving eyes with normal and stable corneas, compared to eyes with frank ectatic diseases and to eyes with normal topography from patients with very asymmetric ectasia, allow for developing advanced methods and testing its sensitivity. However, the ideal study populations for testing the sensitivity and specificity of ectasia risk assessments are respectively the preoperative of cases that developed ectasia and the ones with stable outcomes after LVC. Young age and low thickness are surrogates of corneal biomechanics, which may be replaced as risk factors by direct measurements. Keratectasia may also occur due to the surgical impact on corneal structure or due to significant trauma postoperatively. Percentage tissue altered higher than 40% is a more sensitive parameter than a fixed value for minimal residual stromal bed of 250 ìm. However, the biomechanical impact from surgery is related to the region and number of lamellae that are severed, so that flap thickness and geometry should play a more relevant role, which is in agreement with finite element simulations. Artificial intelligence methods allow for combining parameters, which significantly enhance the accuracy for detecting ectasia risk.

Conclusion: An enhanced screening approach for preventing keratectasia should consider both preoperative patient-related data and procedure-related parameters to individually characterize ectasia susceptibility or predisposition.

Clinical Significance: Keratectasia is an uncommon, however, severe complication of LVC. Although prevention is the best strategy, an individualized enhanced ectasia screening approach for ectasia risk assessment prior to LVC procedures should integrate patient-related (individual ectasia susceptibility) and procedure-related parameters (biomechanical impact).

Keywords: Ectasia susceptibility, Keratectasia, Keratoconus, Laser vision correction.

How to cite this article: Ambrósio Jr R, Belin MW. Enhanced Screening for Ectasia Risk prior to Laser Vision Correction. Int J Kerat Ect Cor Dis 2017;6(1):23-33.

Source of support: Nil

Conflict of interest: None


 
Original Article
Mohammed Othman Abdel Khalek El Sayed, Naglaa Hassan Ali

Incidence and Indices of Keratoconus in Patients presenting for LASIK in Egypt

[Year:2017] [Month:January-June] [Volumn:6 ] [Number:1] [Pages:44] [Pages No:17-22][No of Hits : 644]


ABSTRACT

Background: Keratoconus (KC) is a progressive, non-inflammatory bilateral but (usually asymmetrical) ecstatic corneal disease, characterized by paraxial stromal thinning and weakening that leads to corneal surface distortion. The reported incidence and prevalence of KC varies widely depending upon the geographic location, diagnostic criteria used and the cohort of patients selected.

Aim: To estimate the incidence and indices of KC in patients seeking refractive procedures in Beni Sueif governorate at a span period of one year from March 2013 to March 2014. To describe and analyze the characteristics of the KC population under study.

Materials and methods: This study as designed as a prospective surveillance study. All clinical records in the computerized database from pentacam with the clinical diagnosis of KC and / or suspected were included and statistically analyzed.

Results: Data from 2116 cases with the average 28.8 ± 6.5 years old were analyzed over the span of 1 year starting from March 2013 to March 2014. Based on topographic images of the pentacam 36 eyes were diagnosed as KC. The incidence of KC was 1.7% ( 95% confidence interval, 0.55-1.45). In keratoconic patients, the mean age was 28.1 years, the mean K1 and K2 were 45.18±3.44 D and 49.49 ± 4.28 D respectively. The mean minimal pachymetry value was 463± 6.51um, the mean index of surface variance (ISV) was 61± 32, the mean index of vertical asymmetry (IVA) was 0.63±0.38, the mean keratoconus indices (KI) was 1.08±0.14.

Conclusion: This study provides the first population-based estimate of the incidence of keratoconus in Beni suef governorate in the upper Egypt. According to this study incidence rate of KC is comparable to the rate among the Caucasian people in middle Asia e.g. Iran while incidence rate is much higher among Malaysia and Kingdom of Saudi Arabia citizens.

Keywords: Incidence, Indices, Keratoconus.

How to cite this article: El Sayed MOAK, Ali NH. Incidence and Indices of Keratoconus in Patients presenting for LASIK in Egypt. Int J Kerat Ect Cor Dis 2017;6(1):17-22.

Source of support: Nil

Conflict of interest: None


 
Original Article
Jorge L Alio, Alfredo Vega-Estrada, Pablo Sanz, María J Prieto, Antonio Cardona, Miguel Maldonado Ramon Gutierrez, Rafael I Barraquer, Luis M Sádaba

Distinction between Early Keratoconus with Normal Vision and Normal Cornea based on Pattern Recognition Analysis

[Year:2017] [Month:July-December] [Volumn:6 ] [Number:2] [Pages:64] [Pages No:58-66][No of Hits : 575]


ABSTRACT

Aim: To find the profile that differentiates most normal corneas from early keratoconus with normal vision.

Materials and methods: Multicentric, comparative study including a total of 995 eyes and divided into two groups: 625 eyes suffering from early keratoconus but with normal vision [spectacle corrected distance visual acuity (CDVA) of 0.9 decimal or better] and 370 normal control eyes with same normal vision level. To ascertain the main differences that would allow the identification of the keratoconic eyes from normals, a pattern recognition analysis was performed combining two statistical methods: Principal component analysis (PCA) and discriminant analysis. Visual and refractive parameters, corneal topography, aberrometry, and PCA were evaluated in both groups.

Results: The application of the PCA with Varimax rotation offered a total of five factors which explains the 85.51% of the total variability. Discriminant analysis indicated that factors 1 and 3 were at the greatest discriminating capacity. From a total of 318 cases, the newly identified abnormal pattern profile allowed the recognition of 275, which presents a sensitivity and specificity of 71.6 and 97.3% respectively.

Conclusion: In eyes with normal CDVA, those factors related to the nonorthogonal shape irregularity of the cornea and the refractive power are the ones that showed more discriminating capabilities between normal and early keratoconic eyes.

Clinical significance: Principal component analysis allows to correctly discriminate between normal and mild keratoconus patients; additionally, this method is not restricted to a particular corneal topography technology and is available to any normally equipped ophthalmology office.

Keywords: Discriminant analysis, Keratoconus, Pattern recognition analysis.

How to cite this article: Alio JL, Vega-Estrada A, Sanz P, Prieto MJ, Cardona A, Maldonado M, Gutierrez R, Barraquer RI, Sádaba LM. Distinction between Early Keratoconus with Normal Vision and Normal Cornea Based on Pattern Recognition Analysis. Int J Kerat Ect Cor Dis 2017;6(2):58-66.

Source of support: Nil

Conflict of interest: None


 
Case Report
David P Pinero, Roberto Soto-Negro

Anterior Eye Profilometry-guided Scleral Contact Lens Fitting in Keratoconus

[Year:2017] [Month:July-December] [Volumn:6 ] [Number:2] [Pages:64] [Pages No:97-100][No of Hits : 532]


ABSTRACT

We report the case of a 35-year-old woman diagnosed with keratoconus since she was 18 years old and wearer of corneal rigid contact lenses (CLs). We refitted the case with the fully scleral CL ICD16.5 (Paragon Vision Sciences) for obtaining not only a successful visual restoration, but also a comfortable wear. We initiated the fitting with the spherical model of the CL, but it failed due to instability of the lens. We confirmed the presence of a clear asymmetry in the anterior scleral geometry in both eyes by using the profilometer eye surface profiler (ESP, Eaglet Eye), with a difference between nasal and temporal sagittal heights of 470 and 170 μm in right and left eyes respectively. Although this profile suggested the need for the fitting of a CL with significant peripheral toricity, we followed the manufacturer’s guidelines and performed a trial with a CL of moderate peripheral toricity (125 μm of difference between steep and flat meridian). The stability of the CL failed again and finally a CL with a peripheral toricity close to that measured with the profilometer was fitted. With this lens, good visual performance, lens stability, and comfort was obtained and maintained during a 1-year follow-up. This case suggests that fully scleral CLs fitting might be optimized with the use of corneo-scleral profilometers, minimizing potentially the number of trials. This potential benefit should be investigated further in future studies.

Keywords: Contact lenses, Gas-permeable contact lenses, Keratoconus, Sclera.

How to cite this article: Pinero DP, Soto-Negro R. Anterior Eye Profilometry-guided Scleral Contact Lens Fitting in Keratoconus. Int J Kerat Ect Cor Dis 2017;6(2):97-100.

Source of support: Nil

Conflict of interest: None


 
Review Article
Damien Gatinel

Eye Rubbing, a Sine Qua Non for Keratoconus?

[Year:2016] [Month:January-April] [Volumn:5 ] [Number:1] [Pages:51] [Pages No:6-12][No of Hits : 4305]


ABSTRACT

Keratoconus, a dystrophy of unknown origin, remains an ophthalmic enigma. The contrast between the presence of marked structural changes and deformation of the corneal wall and the relative absence of specific genetic and biomolecular findings continues to intrigue ophthalmologists. In Marfan syndrome, where genetic and molecular abnormalities are well identified, and similar changes in collagen observed, the cornea tends not to be steeper, irregular or ectatic, but are globally flatter. This suggests that an external mechanical force may be necessary to induce the apparition and progression of the ectatic process in keratoconus. Eye rubbing has long been acknowledged as a risk factor for keratoconus and its progression, but could it in fact be the root cause? Many clinical observations and reports support the hypothesis of eye rubbing as a first and necessary hit for inducing progressive ectatic deformation of the corneal wall. Validating or refuting this hypothesis on the basis of patient admission may be impossible. It is difficult to document the frequency, duration and intensity of eye rubbing in patients with keratoconus, and virtually impossible to prove that every patient who denies the habit truly does not rub his eyes. Both the increase in incidence of atopy and the time spent in front of the computer screen in the general population may account for an increased tendency for eye rubbing, and lead to the perceived increased prevalence of keratoconus in both urban and non-urban areas. This paper explores the possibility that the mechanical stress imposed on the cornea by rubbing may not be as much a second hit evoking the structural changes of a predisposed cornea exhibiting unknown collagen progressive alteration, but rather the necessary trigger and sine qua non of the keratoconic process. Even if this provocative hypothesis is impossible to prove, it is equally difficult to refute, and acknowledging eye rubbing as a possible root cause increases awareness within the general population and if true, could dramatically reduce the incidence of keratoconus, and halt its progression in eyes already affected.

Keywords: Computer vision syndrome, Corneal biomechanics, Crosslinking, Ectasia, Eye rubbing, Etiology of keratoconus, Keraotoconus, Marfan syndrome.

How to cite this article: Gatinel D. Eye Rubbing, a Sine Qua Non for Keratoconus? Int J Kerat Ect Cor Dis 2016;5(1):6-12.

Source of support: I thank Cordelia Chan, MD, for assisting the revision of the manuscript.

Conflict of interest: None


 
Review Article
Hagar Hefner-Shahar, Nir Erdinest

High-order Aberrations in Keratoconus

[Year:2016] [Month:September-December] [Volumn:5 ] [Number:3] [Pages:45] [Pages No:128-131][No of Hits : 1900]


ABSTRACT

With all the technological advances today and the increasing number of people undergoing refractive surgery, the importance of detecting keratoconus (KC) prior to surgery has become evident. Although by using a topographer we can detect early stage KC, however, by using wavefront analysis technology, we are able to detect KC at an even earlier stage.
Every eye possesses a number of aberrations. However, in a KC patient’s eye, there are approximately five to six times the numbers of high-order aberrations (HOAs) than in a healthy eye. Using this technology to detect and assess the HOAs, it was found that in a KC cornea, it is possible to detect at a very early stage a much higher value of vertical coma aberrations compared with a normal eye. By using this technology, it is possible to study and understand the characteristics of the quality of the image on the retina, thereby understanding its impact on the patient’s visual quality.

Keywords: Aberrations, High-order, Keratoconus, Vertical coma, Wavefront.

How to cite this article: Hefner-Shahar H, Erdinest N. Highorder Aberrations in Keratoconus. Int J Kerat Ect Cor Dis 2016;5(3):128-131.

Source of support: Nil

Conflict of interest: None


 
Review Article
Paolo Vinciguerra, Raffaele Piscopo, Fabrizio Camesasca, Riccardo Vinciguerra

Progression in Keratoconus

[Year:2016] [Month:January-April] [Volumn:5 ] [Number:1] [Pages:51] [Pages No:21-31][No of Hits : 1861]


ABSTRACT

The study of keratoconus progression was once based upon slitlamp study, keratometry, and placido disk image examination. Today we have a lot of new corneal devices and indexes wich can help the ophthalmologist to make earlier the diagnosis and also to recognize as much is possible a progressive keratoconus. Only a deep knowledge of the meaning of all these indexes and values, together with the ability to interlock one another, increases reliability in the evaluation of Corneal Ectasia. Some pratical instructions are provided to help the early diagnosis of progressive Keratoconus.

Keywords: Corneal tomography, Corneal topography, Ectasia, Keratoconus.

How to cite this article: Vinciguerra P, Piscopo R, Camesasca F, Vinciguerra R. Progression in Keratoconus. Int J Kerat Ect Cor Dis 2016;5(1):21-31.

Source of support: Nil

Conflict of interest: None


 
Case Report
Adel Barbara, Ramez Barbara

Late-onset Post-Lasik Ectasia with no Apparent Risk Factor except Eye Rubbing: A Case Report and Literature Review

[Year:2016] [Month:May-August] [Volumn:5 ] [Number:2] [Pages:39] [Pages No:85-91][No of Hits : 1029]


ABSTRACT

Post-lasik ectasia is the most feared complication following lasik, occurring in majority of cases within 1 year of surgery. Furthermore, it is reported many years after surgery. In this case report, we describe and analyze a post-lasik ectasia case in one eye which was diagnosed after 11 years without any risk factor or apparent reason except eye rubbing.

Keywords: Corneal biomechanics, Eye rubbing, Flap thickness, Keratoconus, Keratoectasia, Lasik, Post-lasik ectasia, Residual stromal bed.

How to cite this article: Barbara A, Barbara R. Late-onset Post-lasik Ectasia with no Apparent Risk Factor except Eye Rubbing: A Case Report and Literature Review. Int J Kerat Ect Cor Dis 2016;5(2):85-91.

Source of support: Nil

Conflict of interest: None


 
Case Report
Isaac C Ramos, Dan Z Reinstein, Timothy J Archer, Marine Gobbe, Marcella Q Salomão, Bernardo Lopes, Allan Luz, Fernando Faria-Correia, Damien Gatinel, Michael W Belin, Renato Ambrósio Jr

Unilateral Ectasia characterized by Advanced Diagnostic Tests

[Year:2016] [Month:January-April] [Volumn:5 ] [Number:1] [Pages:51] [Pages No:40-51][No of Hits : 999]


ABSTRACT

To describe a case of very asymmetric ectasia successfully treated by femtosecond laser-assisted intracorneal ring segment implantation, in which the diagnosis of unilateral ectasia in the right eye was based on the clinical findings including history, follow-up, and advanced diagnostic data. The patient’s history was positive for ocular allergy with moderateto- intense eye rubbing only in the right eye. The uncorrected distance visual acuity was 20/63 in the right eye and 20/32 in the left eye. The corrected distance visual acuity (CDVA) was 20/40 in the right eye (-1.75-4.00 × 35°) and 20/16 in the left eye (-0.50-0.25 × 115°). After femtosecond laser-assisted intracorneal ring segment implantation, the right eye improved CDVA to 20/20-1. Concerning ectasia/keratoconus diagnosis, the left eye remained stable over 1 year of follow-up with unremarkable topometric, tomographic, and biomechanical findings. Epithelial thickness mapping by spectral domain optical coherence tomography and very-high-frequency digital ultrasound demonstrated epithelial thickness within normal limits in the left eye. Advanced diagnostic methods along with clinical data enable the distinction from unilateral ectasia cases and subclinical (fruste) keratoconus. Literature review is also performed along with case presentation and discussion.

Keywords: Corneal tomography, Keratoconus, Unilateral ectasia.

How to cite this article: Ramos IC, Reinstein DZ, Archer TJ, Gobbe M, Salomão MQ, Lopes B, Luz A, Faria-Correia F, Gatinel D, Belin MW, Ambrósio R Jr. Unilateral Ectasia characterized by Advanced Diagnostic Tests. Int J Kerat Ect Cor Dis 2016;5(1):40-51.

Source of support: Nil

Conflict of interest: Drs. Ambrósio and Belin are consultants for Oculus (Wetzlar, Germany); Dr. Reinstein is a consultant for Carl Zeiss Meditec (Carl Zeiss Meditec AG, Jena, Germany) and has proprietary interest in the Artemis technology (ArcScan Inc, Morrison, Colorado, USA) through patents administered by the Center for Technology Licensing at Cornell University (CTL), Ithaca, New York, USA. Dr. Gatinel is a consultant for TECHNOLAS Perfect Vision (Munich, Germany). The remaining authors have no proprietary or financial interest in the materials presented herein.


 
Review Article
Suruchi Gupta

Implantable Contact Lenses in Keratoconus

[Year:2016] [Month:January-April] [Volumn:5 ] [Number:1] [Pages:51] [Pages No:17-20][No of Hits : 935]


ABSTRACT

Keratoconus is a progressive inherited disorder with varying economic and social consequences. Varying modalities of visual rehabilitation such as spectacles, contact lenses, surgical treatment in the form of corneal collagen cross-linking to arrest progression, and surface refractive procedures such as photorefractive keratectomy, implantation of phakic intraocular lenses (IOLs), or Intacs have been undertaken with varying results. This review article focuses on the introduction of phakic IOLs/implantable contact lenses in keratoconus. Thorough research was made on PubMed, Google, HINARI, and related sites for all related material, and it was thoroughly studied to draft this article.

Keywords: Corneal collagen cross-linking, Implantable contact lens, Keratoconus, Toric.

How to cite this article: Gupta S. Implantable Contact Lenses in Keratoconus. Int J Kerat Ect Cor Dis 2016;5(1):17-20.

Source of support: Nil

Conflict of interest: None


 
Case Series
Lily Karmona, Tzahi Sela, Oz Franco, Avi Shoshani, Gur Munzer, Igor Kaiserman

Simultaneous Topography-guided Surface Ablation with Collagen Cross-linking for Keratoconus

[Year:2016] [Month:May-August] [Volumn:5 ] [Number:2] [Pages:39] [Pages No:71-76][No of Hits : 840]


ABSTRACT

Purpose: In this article, we present the results of eight eyes of patients who underwent combined same-day partial topographyguided surface ablation followed by accelerated collagen cross-linking (CXL) procedure at Care-Vision Laser Centers to achieve stabilization of corneal ectasia and enhance visual rehabilitation in keratoconus.

Materials and methods: A retrospective nonrandomized review of 8 eyes of 6 patients who underwent the Athens Protocol for progressive keratoconus. Each patient underwent topography-guided ablation followed by CXL procedure.

Follow-up: Follow-up was done on day 1, day 7, and then at 1, 3, 6, and 12 months.

Results: There was a rapid and significant improvement in uncorrected visual acuity and best-corrected visual acuity in 100% eyes, a reduction of keratometric values, and symmetry between vertical hemimeridians. Topographic evaluation showed a marked improvement in irregularity. There were no signs of keratoconic progression noted in any of the eyes on last follow-up. No adverse events were reported in any patient.

Conclusion: Simultaneous surface ablation + CXL seems to be a promising treatment capable of offering patients functional vision and halting progression of the disorder.

Precis: Simultaneous topography-guided custom ablation treatment and photorefractive keratectomy with CXL offers keratoconic patients intolerant to contact lenses both stabilization of the cornea and improved functional vision with spectacles correction.

Keywords: Athens protocol, Keratoconus, Topography-guided surface ablation.

How to cite this article: Karmona L, Sela T, Franco O, Shoshani A, Munzer G, Kaiserman I. Simultaneous Topography-guided Surface Ablation with Collagen Cross-linking for Keratoconus. Int J Kerat Ect Cor Dis 2016;5(2):71-76.

Source of support: Nil

Conflict of interest: None


 
Research Article
Jörg H Krumeich, Nino Hirnschall

Effect of Circular Keratotomy on Progression of Keratoconus

[Year:2016] [Month:May-August] [Volumn:5 ] [Number:2] [Pages:39] [Pages No:57-62][No of Hits : 771]


ABSTRACT

Purpose: Studies on keratoconus treatment with regard to the stage of the disease have not been published. We evaluated patient outcomes over a 5-year period after circular keratotomy (CKT) to treat stage I and II progressive keratoconus.

Setting: Clinic Krumeich, Bochum, Germany.

Design: Retrospective clinical study.

Materials and methods: We retrospectively evaluated the outcomes of 185 consecutive CKT procedures to treat early, progressing keratoconus. A 7-mm trephine incision, with a depth that was 90% of the thinnest pachymetry value but not less than 400 µm, was made with the guided trephine system concentric to the pupil and sutured with a double running anti-torque suture. Keratometry readings and astigmatism measurements at 1-year postsurgery were compared with values obtained at 3 and 5 years postsurgery. Preoperative values of best-corrected visual acuity with glasses were compared with values obtained at 3 and 5 years postsurgery. Statistical analyses for significance were performed.

Results: Keratometric readings revealed stability at 5 years postsurgery in 84.3% (n = 51) of those eyes for which all values at all time points were available. Likewise, astigmatism values revealed stability in 92.2% of eyes. Best-corrected visual acuity improved significantly from preoperative to 5 years in 73.68% (n = 38). Best-corrected visual acuity did not change in 18.42% (n = 36).

Conclusion: Circular keratotomy halted the progression of early-stage keratoconus for at least 5 years in 84.3% of the eyes studied. The stable keratometric results suggest that CKT treatment should be considered for patients diagnosed early in the progression of this disease.

Keywords: Circular keratotomy, Guided trephine system, Keratoconus treatment.

How to cite this article: Krumeich JH, Hirnschall N. Effect of Circular Keratotomy on Progression of Keratoconus. Int J Kerat Ect Cor Dis 2016;5(2):57-62.

Source of support: Nil

Conflict of interest: None


 
Original Article
Nagla Hassan Ali, Mohammed Othman AbdElKhalek, Hanan Elghoneimy

Comparison of Anterior Chamber Parameters between Normal and Keratoconus Eyes using Scheimpflug Photography

[Year:2016] [Month:September-December] [Volumn:5 ] [Number:3] [Pages:45] [Pages No:105-108][No of Hits : 763]


ABSTRACT

Aim: To evaluate anterior chamber indices including anterior chamber depth (ACD) and anterior chamber volume (ACV) with the progression of keratoconus using a rotating Scheimpflug camera to determine the sensitivity and specificity of these parameters in discriminating keratoconus from normal eyes.

Materials and methods: After full ophthalmological examination in the Memorial Institute of Ophthalmic Research, the patients are divided into two groups: Group I consisting of 50 eyes of normal control. Group II consists of 50 eyes of moderate keratoconus. All the subjects were evaluated with a Pentacam Scheimpflug camera (Oculus, Wetzlar, Germany). Keratoconic eyes were evaluated by vertical asymmetry (VI), keratoconus index (KI), thinnest corneal thickness (TCT) with front elevation at thinnest location (F.Ele.Th) and back elevation at thinnest location (B.Ele.Th) and then divided into three groups according to mean keratometer (K) readings: Mild (K = less than 47.0 D), moderate (K = 47.0 to 52.0 D), and severe (K = 52.0 D or higher), and ACD and ACV were obtained after exclusion of mild and severe cases.

Results: With the progression of the disease, there was statistically significant differences in ACD and ACV measurements between the normal and moderate keratoconus eyes with progressive increase in the ACD and ACV with disease progression.

Conclusion: Anterior chamber parameters including depth and volume showed significant increase with moderate keratoconus than control.

Keywords: Anterior, Photography, Scheimpflug.

How to cite this article: Ali NH, AbdElKhalek MO, El Ghonemy HM. Comparison of Anterior Chamber Parameters between Normal and Keratoconus Eyes using Scheimpflug Photography. Int J Kerat Ect Cor Dis 2016;5(3):105-108.

Source of support: Nil

Conflict of interest: None


 
Case Series
Liat Gantz, Ariela Gordon-Shaag, Arige Gideon-Abousaid, Gad Serero, Philip Fine

Keratoconic Bi-aspheric Contact Lenses

[Year:2016] [Month:September-December] [Volumn:5 ] [Number:3] [Pages:45] [Pages No:132-138][No of Hits : 731]


ABSTRACT

Aim: This observational clinical case series examined patients with keratoconus (KC) fit with keratoconic bi-aspheric (KBA) lenses to assess visual acuity (VA), wavefront aberrations, physiological fitting, subjective comfort, and manufacturer’s fitting guidelines.

Materials and methods: Seven adult patients (11 eyes, four females, mean age: 34.15 ± 14.12) with nipple cones from the Hadassah Academic College contact lens clinic (Jerusalem, Israel) were fit with KBA lenses by modifying the initial base curve (BC) to obtain an acceptable physiological fit. The uncorrected and corrected distance (D) and near (N) Snellen VA and the ocular wavefront measurements, and responses to a self-administered five-point scale questionnaire were compared after 2 weeks of wear using paired two-tailed t-test or Mann- Whitney U test, as appropriate.

Results: Visual acuity and total root mean square (RMS) improved significantly with the lenses (DVAuncorrected = 0.04 ± 0.02, DVAcorrected = 0.66 ± 0.22, NVAuncorrected = 0.34 ± 0.30, NVAcorrected = 0.95 ± 0.12). Subjects reported an average of 7.0 ± 2.7 hours of wear daily, with good scores in visual stability, satisfaction with VA and quality of vision, improvement of mood and quality of life, and low scores in foreign body sensation, pain, red eye, and itching during wear, and difficulty with lens removal. An average of two BC modifications from the diagnostic lens were necessary (0.16 mm steeper in nine eyes, 0.27 mm flatter in two eyes).

Conclusion: Keratoconic bi-aspheric lenses can provide 7 hours of comfortable wear, significantly improved VA and total RMS aberrations, alongside subjective satisfaction. Base curve modifications can be reduced by fitting a diagnostic lens 0.75 mm steeper than the flattest keratometry reading.

Keywords: Contact lenses, Gas permeable contact lenses, Higher order aberrations, Keratoconus, Visual acuity.

How to cite this article: Gantz L, Gordon-Shaag A, Gideon- Abousaid A, Serero G, Fine P. Keratoconic Bi-aspheric Contact Lenses. Int J Kerat Ect Cor Dis 2016;5(3):132-138.

Source of support: Nil

Conflict of interest: None


 
Original Article
Kyaw L Tu, Abdo K Tourkmani, Singaram Srinivas

Keratoconic Cone Using its Keratometry, Decentration, and Thickness as Staging Parameters

[Year:2016] [Month:September-December] [Volumn:5 ] [Number:3] [Pages:45] [Pages No:99-104][No of Hits : 717]


ABSTRACT

Aim: To propose a new system of keratoconus staging using a set of parameters describing the keratoconic cone.

Materials and methods: Retrospective case series study of 101 keratoconic eyes of 58 patients was undertaken. They all had complete eye examination including corneal topography (Oculus Pentacam). Kmean, Kmax, higher order aberrations (HOAs) root mean square (HOARMS) value, pachymetry at thinnest point and steepest corneal meridian were obtained from Pentacam. Apex to thinnest pachymetry distance (D) was calculated using trigonometry. Pearson correlation coefficients between Kmax and HOARMS, between D on the one hand and the adjusted angle of steepest meridian, Kmean and Kmax respectively on the other, were calculated.

Results: There is a statistically significant positive correlation between Kmax and HOARMS (p < 0.00001). There is a negative correlation, a “horizontalization,” of the steep meridian with D increase, although it fell short of statistical significance (p = 0.07). D and Kmean (p = 0.003), and D and Kmax (p = 0.005) are significantly negatively correlated.

Conclusion: Kmax correlates with significant changes in HOAs. D correlates with corneal astigmatic meridian change and has a divergent path to Kmean and to Kmax. We propose a new keratometry, decentration, and thinnest pachymetry staging using the parameters Kmax (K), distance from the corneal apex to the thinnest pachymetry point (D), and corneal thickness at its thinnest point (T) to give a better, detailed description of a keratoconic cornea which could lead to improvements in assessment of its severity and treatment outcomes.

Keywords: Decentration, Keratometry, Thickness.

How to cite this article: Tu KL, Tourkmani AK, Srinivas S. Keratoconic Cone using its Keratometry, Decentration and Thickness as Staging Parameters. Int J Kerat Ect Cor Dis 2016;5(3):99-104.

Source of support: Nil

Conflict of interest: None


 
Editorial
Renato Ambrosio, Fernando Faria-Correia, Bernardo Lopes, Marcella Salomão, Michael W Belin

Evolution on Keratoconus and Corneal Ectatic Diseases: Paradigms and Paradoxes

[Year:2016] [Month:September-December] [Volumn:5 ] [Number:3] [Pages:45] [Pages No:iv-vii][No of Hits : 686]


ABSTRACT

The first accurate description of keratoconus is reported to be the treatise on conical cornea published by Dr John Nottingham in London, in 1854. Interestingly, despite the limitations on the knowledge related to anatomy, biochemistry, and physiology of the eye, Nottingham’s seminal work described in detail many aspects of the epidemiology, clinical presentation, and treatment of corneal ectatic diseases are still accurate today.1


 
Review Article
Shiji Ummar, Abdelsattar N Farrag

Corneal Collagen Cross-linking in Infective Keratitis

[Year:2016] [Month:January-April] [Volumn:5 ] [Number:1] [Pages:51] [Pages No:13-16][No of Hits : 675]


ABSTRACT

Purpose of review: To summarize the current understanding of effects of cross-linking (CXL) in infective keratitis based on available evidence.

Method of literature search: A PubMed search was conducted with combinations not limited to the following search terms: corneal collagen CXL, riboflavin, ultraviolet A, keratoconus, microbial keratitis, fungal keratitis, bacterial keratitis, Acanthamoeba keratitis. A review of the search results was performed and relevant articles to the topic were included.

Summary: Most of the published literature showed promising results in treatment of infectious keratitis by corneal collagen CXL using photoactivated riboflavin as an adjuvant therapy but with questionable efficacy in deep keratitis due to slowgrowing organisms.

How to cite this article: Ummar S, Farrag AN. Corneal Collagen Cross-linking in Infective Keratitis. Int J Kerat Ect Cor Dis 2016;5(1):13-16.

Source of support: Nil

Conflict of interest: None


 
Case Series
José RC Reis, Alberto Diniz-Filho, Fábio M Rocha, Leonardo Torquetti

Pathogenesis of Fixed Dilated Pupil (Urrets-Zavalía Syndrome) after Deep Lamellar Keratoplasty in Keratoconus

[Year:2016] [Month:January-April] [Volumn:5 ] [Number:1] [Pages:51] [Pages No:32-34][No of Hits : 662]


ABSTRACT

Purpose: To present a case series of patients that developed Urrets-Zavalia syndrome (UZS) after deep anterior lamellar keratoplasty (DALK) for treating keratoconus and discuss the mechanisms for the syndrome.

Materials and methods: Retrospective chart analysis of patients who developed UZS after DALK at the Cornea Unit, Hospital São Geraldo, Federal University of Minas Gerais.

Results: We present a series of 3 patients with features consistent with UZS, after undergoing DALK. Elevated intraocular pressure (IOP) was noted in the early postoperative period in 2 cases, despite the fact that the other case reported eye pain, headache, and nausea at the night after the surgery with undocumented IOP. Although at different extents, the pupil remained atrophic and dilated in all 3 eyes, and 2 of them developed anterior subcapsular cataract.

Conclusion: Iris ischemia resulting from occlusion of iris root vessels due to elevated IOP higher than diastolic blood pressure causes UZS. Elevated IOP should be monitored, especially in young patients with low diastolic blood pressure, in order to avoid the occurrence of the syndrome.

Keywords: Cornea, Keratoconus, Keratoplasty, Pupil.

How to cite this article: Reis JRC, Diniz-Filho A, Rocha FM, Torquetti L. Pathogenesis of Fixed Dilated Pupil (Urrets-Zavalía Syndrome) after Deep Lamellar Keratoplasty in Keratoconus. Int J Kerat Ect Cor Dis 2016;5(1):32-34.

Source of support: Nil

Conflict of interest: None


 
Research Article
Andreas Prangl-Grötzl, Armin Ettl, Robert Hörantner, Albert Daxer

Individual Long-term Visual Stability after MyoRing Treatment of Keratoconus

[Year:2016] [Month:May-August] [Volumn:5 ] [Number:2] [Pages:39] [Pages No:53-56][No of Hits : 593]


ABSTRACT

Purpose: The article aims to study the individual long-term stability of visual acuity after MyoRing treatment of keratoconus.

Materials and methods: This is a retrospective study of the individual visual acuity development for 5 years after MyoRing implantation for keratoconus.

Results: In no single case did uncorrected and corrected distance visual acuity lose one line or more during the first 5 years after MyoRing treatment for keratoconus. Moreover, visual acuity was even further ameliorated in most of the cases until the last follow-up period of 5 years after surgery.

Conclusion: The results indicate that MyoRing placement inside the cornea can achieve both visual rehabilitation and stop of progression of the disease.

Keywords: Corneal ring, Keratoconus, MyoRing, Stop of progression, Visual rehabilitation.

How to cite this article: Prangl-Grötzl A, Ettl A, Hörantner R, Daxer A. Individual Long-term Visual Stability after MyoRing Treatment of Keratoconus. Int J Kerat Ect Cor Dis 2016;5(2):53-56.

Source of support: The study was partly supported by the Austrian Research Fund (FFG).

Conflict of interest: Dr. Daxer has an investment interest in DIOPTEX GmbH, Dr. Prangl-Grötzl, Dr. Ettl, and Dr. Hörantner have no financial interest. Preliminary results were presented at the Keratoconus Expert Meeting held during the annual meetings of the ESCRS 2014 in London and 2015 in Barcelona.


 
Original Article
Marcella Q Salomão, Fernando F Correia, Isaac Ramos, Allan Luz, Renato Ambrósio Jr

Corneal Deformation Response with Dynamic Ultra-high-speed Scheimpflug Imaging for Detecting Ectatic Corneas

[Year:2016] [Month:January-April] [Volumn:5 ] [Number:1] [Pages:51] [Pages No:1-5][No of Hits : 555]


ABSTRACT

Purpose: To test the ability of metrics derived from corneal response to noncontact tonometry (NCT) to distinguish between normal and ectatic cases.

Materials and methods: The prototype of CorVis ST (Oculus, Wetzlar, Germany) was used for assessing corneal biomechanical response using ultra-high-speed 8 mm horizontal Scheimpflug photography, taking 4,330 frames per second during NCT. Patients were stratified based on clinical data, including rotating Scheimpflug corneal tomography (Oculus Pentacam HR). Biomechanical data from one eye randomly selected of 177 patients with normal corneas (N) and from 79 patients with bilateral keratoconus (KC) were investigated. Group forme fruste keratoconus (FFKC) was composed of 20 eyes with normal topographic patterns from cases with ectasia detected in the fellow eye. Group keratoconus suspect (KCS) had 16 eyes from 16 patients with topographic patterns suspicious of KC but documented stability over 3 years and normal tomographic findings. A combination of deformation parameters using linear regression analysis (Prototype Factor 1, pF1) was created by the BrAIn (Brazilian Artificial Intelligence on Corneal Tomography and Biomechanics) study group in order to provide the best possible separation of KC and normals.

Results: Statistical significant differences were found for N × KC for several parameters, including first and second applanation times, deformation amplitude, and maximal concavity radius (Mann-Whitney, p < 0.001). However, the areas under the receiver operating characteristic curves (AUC) were lower than 0.90. The pF1 had AUC of 0.945 (IC 0.909-0.97; sensitivity = 87.3% and specificity = 89.3%). The pF1 had statistically significant differences between the ectatic (KC and FFKC) and nonectatic groups (N and KCS) (p < 0.05, Kruskall-Wallis Test with post hoc Dunn’s test).

Conclusion: Corneal deformation response analysis by ultrahigh- speed 8 mm horizontal Scheimpflug photography provides relevant data for distinguishing ectatic and nonectatic corneas but cannot be used independently to detect KC. This data may be integrated with corneal tomography data for enhancing sensitivity and specificity for screening ectasia.

Keywords: Corneal biomechanics, CorVis ST, Forme fruste keratoconus, Keratoconus.

How to cite this article: Salomão MQ, Correia FF, Ramos I, Luz A, Ambrósio R Jr. Corneal Deformation Response with Dynamic Ultra-high-speed Scheimpflug Imaging for Detecting Ectatic Corneas. Int J Kerat Ect Cor Dis 2016;5(1):1-5.

Source of support: Nil

Conflict of interest: None


 
Review Article
Leonardo Torquetti, Jordana Sandes, Guilherme Ferrara, Paulo Ferrara

Ferrara Intrastromal Corneal Ring Segments

[Year:2016] [Month:September-December] [Volumn:5 ] [Number:3] [Pages:45] [Pages No:114-127][No of Hits : 551]


ABSTRACT

The Ferrara intrastromal corneal ring segments (ICRS) are designed to treat ectatic corneal disorders, especially keratoconus. They have been used to reshape keratoconic corneas to improve uncorrected visual acuity, best-corrected visual acuity, contact lens tolerance and to delay or prevent the need for keratoplasty. Intrastromal corneal ring segments have several distinct and important advantages. The Ferrara ICRS have been used largely in several countries for the treatment of primary and secondary ectatic corneal disorders. This article reviews the latest data published and the clinical experience/findings on the treatment of keratoconus by the Ferrara ICRS implantation.

Keywords: Ferrara, Intrastromal corneal ring segments, Keratoconus.

How to cite this article: Torquetti L, Sandes J, Ferrara G, Ferrara P. Ferrara Intrastromal Corneal Ring Segments. Int J Kerat Ect Cor Dis 2016;5(3):114-127.

Source of support: Nil

Conflict of interest: Dr. Paulo Ferrara and Guilherme Ferrara have proprietary interest in the Ferrara ICRS. Dr. Leonardo Torquetti does not have financial interest in any device cited in this review.


 
Original Article
David P Piñero, Alberto Artola, Pedro Ruiz-Fortes, Roberto Soto-Negro, Rafael J Pérez-Cambrodi

Clinical Outcomes at 1 Year following Corneal Ectasia Treatment with Accelerated Transepithelial Cross-linking

[Year:2016] [Month:September-December] [Volumn:5 ] [Number:3] [Pages:45] [Pages No:93-98][No of Hits : 519]


ABSTRACT

Objective: To assess the clinical outcomes in ectatic corneas following accelerated transepithelial cross-linking (CXL) over 1 year of follow-up.

Materials and methods: Twenty-one eyes diagnosed with progressive corneal ectasia (19 keratoconus, 2 post-laser in situ keratomileusis ectasias) in 14 patients aged between 26 and 69 years were enrolled. All cases were treated with accelerated transepithelial CXL using the Avedro KXL® system (Waltham, MA, United States). Changes at visual, refractive, corneal topographic, and corneal aberrometric level were evaluated over a 12-month follow-up period. The demarcation was also determined using optical coherence tomography (OCT).

Results: The mean depth of the demarcation line measured by OCT was 202.72 μm, varying between 153 and 230 μm. One month postsurgery, a change was noted at the limit of statistical significance in sphere (p = 0.05) and in spherical equivalent (p = 0.05). Likewise, a statistically significant difference was observed in corrected distance visual acuity (CDVA) (p = 0.01). There were no significant changes in either visual acuity or refraction between 1 and 6 months (p ≥ 0.35). Although changes in trend were observed in corneal topographic and aberrometric parameters after surgery, none reached statistical significance (p ≥ 0.08). A significant change was observed only in astigmatism of the posterior surface between 1 and 12 months (p = 0.02).

Conclusion: Accelerated transepithelial CXL may be a useful technique for the management of progressive corneal ectasia, as it is able to maintain the topographic and aberrometric profile of the cornea with no significant changes. Longer-term studies are required to confirm this finding

Keywords: Collagen, Corneal, Ectasia.

How to cite this article: Piñero DP, Artola A, Ruiz-Fortes P, Soto-Negro R, Pérez-Cambrodi RJ. Clinical Outcomes at 1 Year following Corneal Ectasia Treatment with Accelerated Transepithelial Cross-linking. Int J Kerat Ect Cor Dis 2016;5(3):93-98.

Source of support: Nil

Conflict of interest: None


 
Jorge L Alió, Alfredo Vega-Estrada, Pablo Sanz-Díez, Pablo Peña-García, María Luisa Durán-García, Miguel Maldonado

Keratoconus Management Guidelines

[Year:2015] [Month:January-April] [Volumn:4 ] [Number:1] [Pages:39] [Pages No:1-39][No of Hits : 13121]


ABSTRACT

This study was partly financed by a project of the Spanish Ministry of Economy and Competitiveness, the Carlos III Health Institute and the Cooperative Health Research Thematic Network on ‘Age-related Eye Disease, Visual Quality and Quality-of-Life’, sub-project ‘Visual Quality’ (RD07/0062); and another project of the Spanish Ministry for Economy and Competitiveness, the Carlos III Health Institute, the Cooperative Health Research Thematic Network ‘Prevention, Early Detection and Treatment of Prevalent, Degenerative and Chronic Eye Diseases’, sub-program ‘Ocular Structures and Common Pathologies’ (RD12/0034).


 
Original Article
Michael W Belin, Josh Duncan, Renato Ambrósio Jr, José AP Gomes

A New Tomographic Method of Staging/Classifying Keratoconus: The ABCD Grading System

[Year:2015] [Month:September-December] [Volumn:4 ] [Number:3] [Pages:37] [Pages No:85-93][No of Hits : 3470]


ABSTRACT

Purpose: To incorporate advanced corneal imaging into a new keratoconus classification system that utilizes posterior curvature, thinnest pachymetry, and best-corrected distance vision (CDVA) in addition to standard anterior parameters.

Materials and methods: A total of 672 eyes of 336 normal patients were imaged with the Oculus Pentacam HR. Anterior and posterior radius of curvature measurements were taken using a 3.0 mm zone centered on the thinnest area and corneal thickness was measured at the thinnest point. Mean and standard deviations were recorded and anterior data were compared to the existing Amsler-Krumeich (AK) classification.

Results: A total of 672 eyes of 336 patients were analyzed. Anterior and posterior values were 7.65 ± 0.236 mm / 6.26 ± 0.214 mm respectively and thinnest pachymetry values were 534.2 ± 30.36 um. Comparing anterior curvature values to AK staging yielded 2.63, 5.47, 6.44 standard deviations for stages 1, 2, and 3 respectively. Posterior staging uses the same standard deviation gates. Comparative pachymetric values yielded 4.42, and 7.72 standard deviations for stages 2 and 3 respectively.

Conclusion: A new keratoconus staging system incorporates posterior curvature, thinnest pachymetric values, and distance visual acuity in addition to the standard anterior curvature and consists of stages 0 to 4 (5 stages), closely matches the existing AK classification stages 1 to 4 on anterior curvature. The new classification system by incorporating curvature and thickness measurements based on the thinnest point, as opposed to apical, better reflects the anatomic changes in keratoconus.

Keywords: Classification, Ectasia, Keratoconus, Radius of curvature.

How to cite this article: Belin MW, Duncan J, Ambrósio R Jr, Gomes JAP. A New Tomographic Method of Staging/ Classifying Keratoconus: The ABCD Grading System. Int J Kerat Ect Cor Dis 2015;4(3):85-93.

Source of support: Nil

Conflict of interest: None


 
Review Article
Cheryl MacGregor, Rakesh Jayaswal, Nick Maycock

Collagen Cross-linking for Pellucid Marginal Degeneration

[Year:2015] [Month:September-December] [Volumn:4 ] [Number:3] [Pages:37] [Pages No:100-102][No of Hits : 2601]


ABSTRACT

Pellucid marginal degeneration (PMD) is a rare progressive condition resulting in inferior corneal thinning and astigmatism. Alongside keratoconus and keratoglobus, it is considered one of noninflammatory corneal ectasias. The focus of corneal thinning is greatest inferiorly resulting in diminished visual acuity and overall reduction in visual quality. Traditional methods of treatment or disease management have been similar to those proposed for keratoconus, contact lenses, escalating to intrastromal rings, lamellar keratoplasty or penetrating keratoplasty.
Collagen cross-linking (CXL) has steadily gained acceptance as the treatment of choice for progressive corneal ectasias. Although it has been described at length for keratoconus, there is little literature describing or advocating its use in PMD. In this article, we will review the evidence for CXL and its use in PMD.

Keywords: Cornea, Corneal collagen cross-linking, Pellucid marginal degeneration, Review article.

How to cite this article: MacGregor C, Jayaswal R, Maycock N. Collagen Cross-linking for Pellucid Marginal Degeneration. Int J Kerat Ect Cor Dis 2015;4(3):100-102.

Source of support: Nil

Conflict of interest: None


 
CASE REPORT
Rosane de Oliveira Corrêa, Ana Laura Caiado Canedo, Rozalia Beildeck, Marcella Quaresma Salomão, Penelope Burle de Politis, Renato Ambrósio Jr

Long-term Stability of Ectasia in a Young Patient with Asymmetric Keratoconus

[Year:2015] [Month:May-August] [Volumn:4 ] [Number:2] [Pages:42] [Pages No:66-68][No of Hits : 1808]


ABSTRACT

Purpose: To report the clinical course of a typical young patient presenting with asymmetric keratoconus (KC), that demonstrates that stabilization of the ectatic process is possible without cross-linking (CXL) procedure.

Methods: Case report and review of the literature.

Results: A 17-year-old male patient was referred due to the diagnosis of keratoconus. Patient complained of loss of vision in the left eye (OS). Uncorrected distance visual acuity (UDVA) was 20/25+ in the right eye (OD) and 20/80 in the left eye; wavefront-assisted manifest refraction gave best corrected distance visual acuity (CDVA) of 20/20 in OD and 20/40 in OS. The diagnosis of keratoconus was confirmed with Placido disk-based topography (Oculus Keratograph 4), and Pentacam HR corneal tomography (Oculus Optikgeräte GmbH, Wetzlar, Germany). Femtosecond laser-assisted intracorneal ring segment (ICRS) implantation was performed in the left eye and treatment for allergy was prescribed for both eyes, along with patient education and advice not to rub the eyes. After 3 months, significant improvement was observed on UDVA (20/30) and CDVA (20/20) in the left eye. Topometric and tomographic stability of ectasia was observed in the right eye in a 4-year follow-up.

Conclusion: Intracorneal ring segment caused significant regularization of the corneal shape and improvement on visual acuity. Ectasia stability was achieved with no need for CXL, despite the patient’s young age. This case raises the point that the indication of CXL for every keratoconic patient should be reconsidered.

Keywords: Cross-linking indication, Intracorneal ring, Keratoconus.

How to cite this article: de Oliveira Correa R, Canedo ALC, Beildeck R, Salomão MQ, de Politis PB, Ambrósio R Jr. Longterm Stability of Ectasia in a Young Patient with Asymmetric Keratoconus. Int J Kerat Ect Cor Dis 2015;4(2):66-68.

Source of support: Nil

Conflict of interest: Dr Ambrósio is a consulant for oculus and wavelight-alcon.


 
CASE REPORT
Marco Abbondanza, Margherita Guidobaldi

Corneal Collagen Cross-linking in a Prepubescent 10-Year-Old Girl with Aggressive Keratoconus

[Year:2015] [Month:May-August] [Volumn:4 ] [Number:2] [Pages:42] [Pages No:63-65][No of Hits : 1707]


ABSTRACT

Keratoconus (KC) is a corneal ectatic disease that results in bilateral and asymmetrical corneal distortion, altered refractive powers and reduced vision. In 20 to 25% of cases, corneal transplantation may be required, although a number of conservative procedures are available. We report a case of an aggressive stage II keratoconus in a prepubescent 10-year-old girl, successfully treated with corneal collagen cross-linking (CXL) with epithelium removal.

Keywords: Cornea, Corneal collagen cross-linking, Keratoconus, Pediatric.

How to cite this article: Abbondanza M, Guidobaldi M. Corneal Collagen Cross-linking in a Prepubescent 10-Year- Old Girl with Aggressive Keratoconus. Int J Kerat Ect Cor Dis 2015;4(2):63-65.

Source of support: Nil

Conflict of interest: None


 
Case Report
Marco Abbondanza, Gabriele Abbondanza

Surgical Correction of an Inverse Astigmatic Keratotomy following Penetrating Keratoplasty in a Patient with Keratoconus

[Year:2015] [Month:September-December] [Volumn:4 ] [Number:3] [Pages:37] [Pages No:107-109][No of Hits : 1228]


ABSTRACT

Astigmatic keratotomy (AK) is a common and safe procedure to correct post-penetrating keratoplasty (PKP) astigmatism in patients affected by keratoconus (KC). We report the case of a post-PKP AK that was performed inversely by mistake in a private practice. A new AK was performed by our practice in order to correct the remarkably high astigmatism (19 D) that was created with the previous inverse procedure. Fourteen months later, astigmatism had decreased by 12.9 D and central corneal thickness had increased by 35 µm.

Keywords: Astigmatic keratotomy, Cornea, Keratoconus, Keratotomy, Lri, Surgical error.

How to cite this article: Abbondanza M, Abbondanza G. Surgical Correction of an Inverse Astigmatic Keratotomy following Penetrating Keratoplasty in a Patient with Keratoconus. Int J Kerat Ect Cor Dis 2015;4(3):107-109.

Source of support: Nil

Conflict of interest: None


 
REVIEW ARTICLE
Prafulla K Maharana, Ritu Nagpal, Namrata Sharma

Corneal Hydrops in Keratoconus

[Year:2015] [Month:May-August] [Volumn:4 ] [Number:2] [Pages:42] [Pages No:52-55][No of Hits : 948]


ABSTRACT

Purpose: The purpose of this review is to outline the etiology, clinical features, and management of acute corneal hydrops (CH) in cases of keratoconus (KC).

Recent findings: The advent of newer investigative modalities like ultra biomicroscopy, anterior segment optical coherence tomography and confocal microscopy has contributed toward the diagnosis, treatment planning and following the course of therapy in cases of acute hydrops.

Summary: Corneal hydrops is an acute complication of keratoconus which in most instances resolves spontaneously. However, prolonged corneal edema can lead to complications, such as corneal neovascularization which can jeopardise a future corneal graft. Hence, timely intervention is required in most cases to prevent such complications as well as for early visual rehabilitation. Intracameral gas injection is the most commonly performed surgical procedure for hydrops. Modifications in surgical technique can help to tackle difficult situations.

Keywords: Acute corneal hydrops, Corneal edema, Intracameral gas injection, Keratoconus.

How to cite this article: Maharana PK, Nagpal R, Sharma N. Corneal Hydrops in Keratoconus. Int J Kerat Ect Cor Dis 2015;4(2):52-55.

Source of support: Nil

Conflict of interest: None


 
Case Report
Mainak Bhattacharyya, Kirti Singh, Ankush Mutreja, Sonal Dangda, Ritu Arora

Diffuse Sterile Corneal Infiltration: An Unusual Complication Post Collagen Cross-linkage

[Year:2015] [Month:September-December] [Volumn:4 ] [Number:3] [Pages:37] [Pages No:115-119][No of Hits : 715]


ABSTRACT

Purpose: Presenting the course of visually disabling corneal infiltration post uneventful collagen cross-linking (CXL) in a 23 years old male with bilateral keratoconus.

Methods: A 23 years old male with bilateral keratoconus underwent cross-linking of left eye with indigenous 0.1% riboflavin dye and 370 nm ultraviolet A irradiation. This patient had an uneventful successful cross-linking performed in right eye 6 months prior with good recovery of vision to LogMAR 0.2 (6/9 Snellen).

Results: Patient developed diminution of vision, along with redness of eye, photophobia and watering on 3rd day after uneventful cross-linkage. Examination revealed very poor vision; diffuse corneal clouding with multiple superficial stromal infiltrates and incomplete corneal epithelization. A provisional diagnosis of infective keratitis was made, in situ bandage contact lens (BCL) removed and subjected to culture. Intensive fortified topical antibiotics were initiated and steroids withheld. After complete corneal re-epithelization on 6th day, the infiltrations did not decrease in either intensity or number. Response to antibiotics being inadequate, an immune etiology was suspected and full strength topical steroids reinstituted which resulted in slow resolution of infiltration over a 10 weeks period. Last follow-up at 9 months post-CXL, revealed a diffuse stromal haze with unaided visual acuity of LogMAR 0.8 6/36 and best-corrected visual acuity (BCVA) of 0.3 (6/12) with use of a rigid gas permeable lens.

Conclusion: Sterile infiltration post-CXL requiring intense topical steroids is a rare complication of CXL and needs to be differentiated from infective keratitis.

Keywords: Cross-linkage, Keratoconus, Sterile infiltrate.

How to cite this article: Bhattacharyya M, Singh K, Mutreja A, Dangda S, Arora R. Diffuse Sterile Corneal Infiltration: An Unusual Complication Post Collagen Cross-linkage. Int J Kerat Ect Cor Dis 2015;4(3):115-119.

Source of support: Nil

Conflict of interest: None


 
REVIEW ARTICLE
Frederik Raiskup, Mark Hillen

Corneal Cross-linking can halt the Progression of Keratoconus, but what is the Best Approach to Treatment?

[Year:2015] [Month:May-August] [Volumn:4 ] [Number:2] [Pages:42] [Pages No:47-51][No of Hits : 704]


ABSTRACT

There are a number of treatment options for keratoconus, but only corneal collagen cross-linking (CXL) appears to halt the progression of the disease. To guarantee effective cross-linking, CXL treatment involves removal of the corneal epithelium prior to riboflavin application and ultraviolet light illumination to ensure that riboflavin reaches the collagen in the stroma-epithelial-on cross-linking (‘Epi-off’ CXL). Several methods of ‘Epi-on’ (transepithelial) CXL have been proposed, as keeping the corneal epithelium intact should be less painful and help avoid other CXL-associated adverse events. The evidence to date is that Epi-off CXL remains the most effective method of strengthening the cornea and slowing keratoconus progression-but transepithelial methods are gaining ground.

Keywords: Corneal collagen cross-linking, ‘Epi-off’ crosslinking, ‘Epi-on’ cross-linking, Keratoconus, Transepithelial cross-linking.

How to cite this article: Raiskup F, Hillen M. Corneal Crosslinking can halt the Progression of Keratoconus, but what is the Best Approach to Treatment? Int J Kerat Ect Cor Dis 2015; 4(2):47-51.

Source of support: Nil

Conflict of interest: None


 
CASE REPORT
David P Piñero Llorens

Fitting of a New Design of Full Scleral Contact Lens in Advanced Keratoconus with Previous Implantation of Intracorneal Ring Segments

[Year:2015] [Month:May-August] [Volumn:4 ] [Number:2] [Pages:42] [Pages No:56-59][No of Hits : 702]


ABSTRACT

This case report reports the visual rehabilitation obtained with the fitting of a new design of full scleral contact lens (ICD 16.5 contact lens, Paragon Vision Sciences, distributed by Lenticon, Madrid, Spain) in a cornea with advanced keratoconus and previous implantation of intracorneal ring segment with a very limited effect. This eye had a refraction of -3.00 × 55° cylinder, providing a visual acuity of 0.5 LogMAR. The topographic pattern was very irregular with the presence of a significant central protrusion and a significant central corneal thinning. Some previous unsuccessful fittings have been performed with corneal and corneal-scleral lenses. A comfortable wearing was achieved with a fully scleral contact lens of 4600 µm of sagittal height, optical power of -11.25 D, and providing an apical clearance of 196 µm. A visual acuity of 0.0 LogMAR combined with a relevant aberrometric improvement was achieved with this contact lens. The patient was completely satisfied with the fitting. The result was maintained during 1 year after the fitting. Full scleral lenses are then able to provide comfortable wear and a significant increase in visual acuity combined with a significant improvement in the visual quality in eyes with advanced keratoconus.

Keywords: Contact lenses, Corneal irregularity corneal asymmetry, Intrastromal corneal rings, Keratoconus, Sirius.

How to cite this article: Llorens DPP. Fitting of a New Design of Full Scleral Contact Lens in Advanced Keratoconus with Previous Implantation of Intracorneal Ring Segments. Int J Kerat Ect Cor Dis 2015;4(2):56-59.

Source of support: Nil

Conflict of interest: None


 
Review Article
Jorge L Alio, Pablo Sanz-Díez

Phakic Intraocular Lenses in Keratoconus

[Year:2015] [Month:September-December] [Volumn:4 ] [Number:3] [Pages:37] [Pages No:103-106][No of Hits : 696]


ABSTRACT

Purpose: To discuss and summarize the indications, contraindications and results in refractive surgery for keratoconus.

Summary: Keratoconus is an ectatic corneal disease characterized by a progressive corneal thinning and irregular astigmatism that negatively impact in the visual function and the optical quality of the patients. The refractive surgery in keratoconus has been discussed by several authors. The two primary lines of action are phakic lens implantation and corneal tissue ablation using photorefractive keratectomy. The use of phakic intraocular lenses (IOLs) to correct myopia and compound myopic astigmatism associated with keratoconus is gaining popularity.

Recent findings: The use of phakic IOLs to correct myopia and compound myopic astigmatism associated with keratoconus is gaining popularity. According to a recent study by our group the safety of this procedure in visual terms is high (post-CDVA/ pre-CDVA = 1.19 ± 0.29). It is also an effective operation (post- UDVA/pre-CDVA = 0.90 ± 0.26).

Keywords: Corneal ectasia, Keratoconus, Phakic intraocular lens, Refractive surgery.

How to cite this article: Alio JL, Sanz-Díez P. Phakic Intraocular Lenses in Keratoconus. Int J Kerat Ect Cor Dis 2015;4(3): 103-106.

Source of support: Nil

Conflict of interest: None


 
CASE REPORT
Albert Daxer

MyoRing Treatment of Keratoconus

[Year:2015] [Month:May-August] [Volumn:4 ] [Number:2] [Pages:42] [Pages No:76-83][No of Hits : 682]


ABSTRACT

A case of bilateral keratoconus after corneal cross-linking in both eyes and ineffective ring segment implantation in the left eye is presented. The ineffective ring segment was removed and instead, a corneal pocket was created and a MyoRing was inserted. In this case study, the currently available options of treatment are presented and the differences between ring segments and MyoRing are discussed in detail.

Keywords: CISIS, ICRS, Keratoconus, MyoRing, Ring segment.

How to cite this article: Daxer A. MyoRing Treatment of Keratoconus. Int J Kerat Ect Cor Dis 2015;4(2):76-83.

Source of support: Nil

Conflict of interest: The author has a financial interest in DIOPTEX GmbH.
The data have been presented in part at the annual meetings of the ESCRS 2013 (Amsterdam) and 2014 (London) as well as at the Keratoconus Expert Meetings 2012 in Milano and 2013 Amsterdam.


 
ORIGINAL ARTICLE
David P Piñero Llorens, Vicente Camps, Esteban Caravaca-Arens

Errors Associated to Keratoconus Grading using Systems based on Corneal Power

[Year:2015] [Month:May-August] [Volumn:4 ] [Number:2] [Pages:42] [Pages No:41-46][No of Hits : 655]


ABSTRACT

Purpose: To analyze and define the possible errors that may be introduced in keratoconus classification when the keratometric corneal power is used in such classification.

Materials and methods: Retrospective study including a total of 44 keratoconus eyes. A comprehensive ophthalmologic examination was performed in all cases, which included a corneal analysis with the Pentacam system (Oculus). Classical keratometric corneal power (Pk), Gaussian corneal power (PcGauss), True Net Power (TNP) (Gaussian power neglecting the corneal thickness effect), and an adjusted keratometric corneal power (Pkadj) (keratometric power considering a variable keratometric index) were calculated. All cases included in the study were classified according to five different classification systems: Alió-Shabayek, Amsler-Krumeich, Rabinowitz- McDonnell, collaborative longitudinal evaluation of keratoconus (CLEK), and McMahon.

Results: When Pk and Pkadj were compared, differences in the type of grading of keratoconus cases was found in 13.6% of eyes when the Alió-Shabayek or the Amsler-Krumeich systems were used. Likewise, grading differences were observed in 22.7% of eyes with the Rabinowitz-McDonnell and McMahon classification systems and in 31.8% of eyes with the CLEK classification system. All reclassified cases using Pkadj were done in a less severe stage, indicating that the use of Pk may lead to the classification of a cornea as keratoconus, being normal. In general, the results obtained using Pkadj, PcGauss or the TNP were equivalent. Differences between Pkadj and PcGauss were within ± 0.7D.

Conclusion: The use of classical keratometric corneal power may lead to incorrect grading of the severity of keratoconus, with a trend to a more severe grading.

Keywords: Corneal topography, Keratoconus, Pentacam.

How to cite this article: Llorens DPP, Camps V, Caravaca- Arens E. Errors Associated to Keratoconus Grading using Systems based on Corneal Power. Int J Kerat Ect Cor Dis 2015;4(2):41-46.

Source of support: Nil

Conflict of interest: None


 
Review Article
Rana Hanna, Eran Berkwitz, Jamyl Habib Castillo, Beatrice Tiosano

Collagen Cross-linking for the Treatment of Keratoconus in Pediatric Patients

[Year:2015] [Month:September-December] [Volumn:4 ] [Number:3] [Pages:37] [Pages No:94-99][No of Hits : 642]


ABSTRACT

Keratoconus (KC) is a bilateral noninflammatory, ectatic corneal disorder. It is the most common primary ectasia affecting approximately 1 in 2,000 in the general population. Classically, the disease starts in puberty and progresses throughout the 3rd or 4th decades of life. Ocular signs and symptoms vary depending on disease severity. As the disease progresses, approximately 20% of KC eyes require penetrating keratoplasty. Collagen cross-linking (CXL) with ultraviolet-A (UVA) light and riboflavin is a new treatment that has emerged in the recent years. It is reported to slow the progression of the disease in its early stages, by increasing corneal rigidity and biomechanical stability. As the number of adult KC patients treated using this procedure grew, proving its safety and high efficacy, the pediatric KC patients population has started to receive special attention. In the pediatric KC patients’ eyes, corneas have been shown to be significantly steeper at the time of diagnosis compared to adults, and the severity of KC seems inversely correlated with age. Since treating KC in earlier age may be beneficiary, before developing an advanced disease that may require corneal transplantation, CXL in the pediatric age group has been advocated by many practitioners. The aim of this review is to collect and consolidate all known data regarding the efficacy and safety of CXL in the pediatric population.

Keywords: Cross-linking, Keratoconus, Pediatric, Review.

How to cite this article: Hanna R, Berkwitz E, Castillo JH, Tiosano B. Collagen Cross-linking for the Treatment of Keratoconus in Pediatric Patients. Int J Kerat Ect Cor Dis 2015;4(3): 94-99.

Source of support: Nil

Conflict of interest: None


 
Case Report
Yakov Goldich, Uri Elbaz, David S Rootman

Anterior Uveitis after Collagen Cross-linking for Keratoconus

[Year:2015] [Month:September-December] [Volumn:4 ] [Number:3] [Pages:37] [Pages No:110-114][No of Hits : 588]


ABSTRACT

This report describes a case of severe intraocular inflammation followed after CXL with UVA and riboflavin treatment for progressive keratoconus.

Keywords: Anterior uveitis, Collagen Cross-linking, Keratoconus.

How to cite this article: Goldich Y, Elbaz U, Rootman DS. Anterior Uveitis after Collagen Cross-linking for Keratoconus. Int J Kerat Ect Cor Dis 2015;4(3):110-114.

Source of support: Nil

Conflict of interest: None


 
Editorial
Renato Ambrósio, Fernando Faria-Correia

MANAGEMENT OF KERATOCONUS

[Year:2015] [Month:January-April] [Volumn:4 ] [Number:1] [Pages:39] [Pages No:v-vii][No of Hits : 539]


ABSTRACT

MANAGEMENT OF KERATOCONUS

Aliò et al are to be commended for the review entitled ‘Keratoconus Management Guidelines’, which adds to the previous classic reviews in this field.1-3 Keratoconus was described for the first time over 150 years ago by John Nottingham. Over the last few decades, there were significant advances on diagnostic and therapeutic technologies, mostly related to refractive surgery. In addition, the relative high incidence of these disorders have stimulated ectatic diseases be considered as a new subspecialty in ophthalmology.4,5


 
CASE REPORT
Adel Barbara, Ramez Barbara

A Special Design of Intacs SK and Collagen Corneal Cross-linking for the Treatment of Pellucid Marginal Degeneration in a 74-Year-Old Male

[Year:2015] [Month:May-August] [Volumn:4 ] [Number:2] [Pages:42] [Pages No:69-75][No of Hits : 526]


ABSTRACT

We present a case report of a 74-year-old male who suffers from advanced and progressive pellucid marginal degeneration in his right eye, his left eye is legally blind because of macular scar.
We performed a combined procedure of a special design Intacs SK insertion followed by epi-off collagen corneal crosslinking according to the Dresden protocol. The Intacs SK were inserted by the manual technique, no intra- or postoperative complications were noted. Two months postoperatively, his uncorrected and best spectacle corrected visual acuity improved, the astigmatism was reduced and regularization of the corneal topography was observed. The patient is very satisfied from the improvement of his vision by minimally invasive procedures.

Keywords: Collagen, Corneal rings, Corneal segments, Crosslinking, ICRS, Intacs, Intrastromal, Keratoconus, Pellucid marginal degeneration, SK, Topography.

How to cite this article: Barbara A, Barbara R. A Special Design of Intacs SK and Collagen Corneal Cross-linking for the Treatment of Pellucid Marginal Degeneration in a 74-Year-Old Male. Int J Kerat Ect Cor Dis 2015;4(2):69-75.

Source of support: Nil

Conflict of interest: None


 
Case Report
Nancy Al Raqqad, Naser Al Fgara

Management of Acanthamoeba and Candida Keratitis in a Young Female: Our Experience at Princess Haya Military Hospital

[Year:2015] [Month:September-December] [Volumn:4 ] [Number:3] [Pages:37] [Pages No:120-122][No of Hits : 525]


ABSTRACT

Aim: We aim to share our experience in the management of a 19 years old female patient, who presented to Princess Haya Military Hospital in Aqaba, Jordan, with a very aggressive keratitis.

Patients and methods: A 19 years old female patient with 1 year history of keratitis that did not resolve despite several treatment strategies tried elsewhere, presented to the eye clinic in Aqaba.
Ocular examination showed signs of Acanthamoeba keratitis with perineuritis.
Corneal cultures were not informative. Corneal biopsy showed a mixed Candida and Acanthamoeba growth.

Results: The patient was started on topical and oral antiamoebic and antifungal treatment (antiamoebic drops brought from UK). Improvement was drastic after 2 weeks of treatment. The patient maintained a chronic low infective state and scarring of the cornea. She received therapeutic and visual karatoplasty 3 months later.
Patient is now 12 months after her PKP. The cornea is clear and vision is 6/12 unaided.

Conclusion: Cases of mixed fungal and amoebic keratitis are very rare. Prompt treatment and diagnosis is essential for recovery. Controversy still exists on the use of steroids after corneal transplantation for treatment of chronic fungal keratitis. Management should be tailored to each individual case.

Keywords: Acanthamoeba, Cornea, Keratitis.

How to cite this article: Al Raqqad N, Al Fgara N. Management of Acanthamoeba and Candida Keratitis in a Young Female: Our Experience at Princess Haya Military Hospital. Int J Kerat Ect Cor Dis 2015;4(3):120-122.

Source of support: Nil

Conflict of interest: None


 
Original Article
Ovette F Villavicencio, Fatimah Gilani, Maria A Henriquez, Luis Izquierdo Jr, Renato R Ambrosio Jr, Michael W Belin

Independent Population Validation of the Belin/Ambrosio Enhanced Ectasia Display: Implications for Keratoconus Studies and Screening

[Year:2014] [Month:January-April] [Volumn:3 ] [Number:1] [Pages:51] [Pages No:1-8][No of Hits : 3185]


ABSTRACT

With advances in technology and imaging, finding diagnostic criteria that are both sensitive and specific for keratoconus while using the latest corneal imaging modalities is paramount. The Belin/Ambrosio enhanced ectasia display final 'D' index, tested on an independent population, illustrated excellent false positive rates for refractive screening while eliminating 99% of keratoconus corneas. A false positive rate of 0% is achieved with a final 'D' of 2.69, meeting the more stringent criteria for treatment studies.

Keywords: Keratoconus, Ectasia, Tomography, Cornea, Imaging, Refractive surgery, Cross-linking, Scheimpflug, Placido, Topography.

How to cite this article: Villavicencio OF, Gilani F, Henriquez MA, Izquierdo L Jr, Ambrosio RR Jr, Belin MW. Independent Population Validation of the Belin/Ambrosio Enhanced Ectasia Display: Implications for Keratoconus Studies and Screening. Int J Kerat Ect Cor Dis 2014;3(1):1-8.

Source of support: Nil

Conflict of interest: Drs Ambrosio and Belin are consultant to OCULUS GmbH.


 
Original Article
Einat Shneor, Michel Millodot, Ariela Gordon-Shaag, Maron Essa, Miriam Anton, Ramez Barbara, Adel Barbara

Prevalence of Keratoconus among Young Arab Students in Israel

[Year:2014] [Month:January-April] [Volumn:3 ] [Number:1] [Pages:51] [Pages No:9-14][No of Hits : 3028]


ABSTRACT

Purpose: To determine the prevalence of keratoconus (KC) in an Arab population in Israel.

Materials and methods: Videokeratography was performed on volunteer students from the Academic Arab College of Education, in Haifa, Israel. All participants filled out a selfadministered questionnaire to evaluate possible risk factors for KC. Univariate and multivariate analysis were performed.

Results: Data of 314 participants were analyzed and a prevalence of (N = 10), 3.18% (95% CI, 1.2 to 5.1%) was found. The only significant factor (both in univariate and multivariate analysis) that was associated with KC was parental consanguinity (OR 5.10, p = 0.02). Druzes and Bedouins had a higher prevalence than Muslims and Christians. However, the differences were not significant possibly due to the small size of the sample.

Conclusion: The result of this study was similar to other studies conducted in the Middle East, which indicate a higher prevalence of KC than in western countries. It is also recommended that people who have consanguinity in their family should be topographically tested to detect the early stages of KC.

Keywords: Keratoconus, Consanguinity, Videokeratography.

How to cite this article: Shneor E, Millodot M, Gordon-Shaag A, Essa M, Anton M, Barbara R, Barbara A. Prevalence of Keratoconus among Young Arab Students in Israel. Int J Kerat Ect Cor Dis 2014;3(1):9-14.

Source of support: Nil

Conflict of interest: None declared


 
Cross-Sectional Study
Maria A Henriquez, Luis Izquierdo Jr, David Danin

Corneal Elevation Values in Normal Eyes, forme fruste Keratoconus and Keratoconus at Different Stages Measured by Scheimpflug Imaging

[Year:2014] [Month:January-April] [Volumn:3 ] [Number:1] [Pages:51] [Pages No:36-39][No of Hits : 2876]


ABSTRACT

Purpose: To compare corneal elevation values in normal eyes, forme fruste keratoconus (FFKC) and different stages of keratoconus using Scheimpflug imaging.

Materials and methods: This prospective, comparative study included 267 eyes (107 normal eyes, 21 FFKC and 139 keratoconus). Keratoconic eyes were divided into four groups according to keratometry values. Maximum posterior elevation (PE) above the (best fit sphere (BFS) at the central 5 mm were measured using the Pentacam (Oculus Optikgeräte GmbH). Receiver operating characteristic curves were used to determine the test’s overall predictive accuracy and to identify optimal cutoff points to discriminate between the groups.

Results: PE had the smallest values in normal eyes and increased in FFKC and each progressive stage of keratoconus. Mean PE was 9.98 ± 5.33 µm in normal eyes, 18.09 ± 9.23 µm in FFKC and 24.97 µm ± 15.89, 37.82 ± 18.64, 46.82 ± 21.41 and 66.07 ± 39.09, in keratoconus stage I, II, III and IV respectively.

Conclusion: Posterior elevation values increased according to the severity of keratoconus disease. PE can be used as indicator of keratoconus progression.

Keywords: Keratoconus, Scheimpflug imaging, Posterior elevation, Amsler-Krumeich.

How to cite this article: Henriquez MA, Izquierdo L Jr, Dañin D. Corneal Elevation Values in Normal Eyes, forme fruste Keratoconus and Keratoconus at Different Stages Measured by Scheimpflug Imaging. Int J Kerat Ect Cor Dis 2014;3(1):36-39.

Source of support: Nil

Conflict of interest: None declared


 
Review Article
Jamyl Habib Castillo, Rana Hanna, Eran Berkowitz, Beatrice Tiosano

Wavefront Analysis for Keratoconus

[Year:2014] [Month:May-August] [Volumn:3 ] [Number:2] [Pages:46] [Pages No:76-83][No of Hits : 2424]


ABSTRACT

Keratoconus is the most common primary corneal ectasia, involving a thinning of the central cornea, leading to irregular corneal astigmatism. Wavefront analysis is an evolving field in the area of corneal surgery, initially designed for laser refractive treatments, but today is growing in importance and application in the diagnosis and treatment of corneal disorders such as keratoconus. In this article we will review the theoretical background of high order aberrations and the wavefront analysis as a tool for the diagnosis of keratoconus.

Keywords: Keratoconus, Wavefront analysis, High order aberrations, Astigmatism, Cornea, Habib zernike polynomials, Vertical coma.

How to cite this article: Castillo JH, Hanna R, Berkowitz E, Tiosano B. Wavefront Analysis for Keratoconus. Int J Kerat Ect Cor Dis 2014;3(2):76-83.

Source of support: Nil

Conflict of interest: None


 
Original Article
Albert Daxer

Corneal Thickness after MyoRing Implantation for Keratoconus

[Year:2014] [Month:January-April] [Volumn:3 ] [Number:1] [Pages:51] [Pages No:15-19][No of Hits : 2320]


ABSTRACT

Purpose: To analyze the corneal thickness development after MyoRing implantation as a tissue-related indicator of keratoconus progression.

Materials and methods: Twelve eyes suffering from keratoconus were treated for visual rehabilitation by means of MyoRing implantation into a corneal pocket. The postoperative development of the corneal thickness at the thinnest point was analyzed. Follow-up ranged from 16 to 74 months (mean 37 months).

Results: Out of the 12 eyes only one eye showed a thinner cornea at the last follow-up 60 months after MyoRing implan-tation compared to the last preoperative data. None of these 12 eyes required an additional intervention like corneal cross-linking, explantation or keratoplasty. Four eyes showed even thickening of the cornea during the postoperative period.

Conclusion: MyoRing implantation for keratoconus does not only allow visual rehabilitation. It also seems to stop the progression of the disease by creating a new biomechanical equilibrium within the tissue which eliminates a constant stimulus that drives the vicious circle of progression.

Keywords: Keratoconus, MyoRing, Corneal thickness, Progression, Corneal cross-linking, PocketMaker.

How to cite this article: Daxer A. Corneal Thickness after MyoRing Implantation for Keratoconus. Int J Kerat Ect Cor Dis 2014;3(1):15-19.

Source of support: Nil

Conflict of interest: None declared


 
Case Report
Noa Avni-Zauberman, David S Rootman

Post Lasik Keratoectasia Developing with Sleep Apnea and Floppy Eyelid Syndrome: Case Report and Review of the Literature

[Year:2014] [Month:January-April] [Volumn:3 ] [Number:1] [Pages:51] [Pages No:44-46][No of Hits : 2231]


ABSTRACT

We report a case of unilateral keratoectasia in a patient who underwent uneventful hyperopic LASIK 8 years prior and was diagnosed with obstructive sleep apnea syndrome (OSAS) and Floppy eyelid syndrome. The before and after LASIK topographies demonstrated clear development of the ectasia after the patient developed OSAS. The patient was treated with collagen crosslinking in the involved eye to stop ectatic progression. Our report emphasizes the importance of inquiring about the patient’s sleeping postures and habits (specifically asking about OSAS) and a careful examination of eyelid laxity prior to refractive laser treatment.

Keywords: Post-LASIK ectasia, Floppy eyelid syndrome, Obstructive sleep apnea syndrome.

How to cite this article: Zauberman NA, Rootman DS. Post- Lasik Keratoectasia Developing with Sleep Apnea and Floppy Eyelid Syndrome: Case Report and Review of the Literature. Int J Kerat Ect Cor Dis 2014;3(1):44-46.

Source of support: Nil

Conflict of interest: None


 
Original Article
Albert Daxer

MyoRing Treatment for Cases of Myopia not eligible for Laser Vision Correction

[Year:2014] [Month:January-April] [Volumn:3 ] [Number:1] [Pages:51] [Pages No:20-22][No of Hits : 2200]


ABSTRACT

Purpose: MyoRing implantation has been shown to be able to mechanically stabilize ectatic corneas like a bone-nail for broken legs do. Here I present typical cases of MyoRing treatment for Myopia which were not eligible for LASIK.

Materials and methods: Four eyes of four patients suffering from moderate to high myopia and showing risk factors for postoperative ectasia have been treated by MyoRing implantation. Two of them have been combined with laser vision correction (LVC).

Results: The refractive results are comparable to those published for LVC. The cases with combined MyoRing LASIK treatment performed slightly better postoperatively than those treated with MyoRing only.

Conclusion: MyoRing implantation is safe and effective in myopic cases presenting with mainfest signs of keratoconus. In myopic eyes without manifest keratoconus but risk factors for post-LASIK keratectasia the combination of MyoRing implantation with Excimer Laser Surface Ablation may be a good treatment option.

Keywords: Myopia, MyoRing, Lasik, LVC, Keratectasia, PocketMaker, Wavelight, CISIS.

How to cite this article: Daxer A. MyoRing Treatment for Cases of Myopia not eligible for Laser Vision Correction. Int J Kerat Ect Cor Dis 2014;3(1):20-22.

Source of support: Nil

Conflict of interest: None declared


 
Case Report
Luis Claudio Pereira, Renata Siqueira, Bruno Valbon, Rodrigo Santos, Daniel Dawson, Renato Ambrosio, Jorge Augusto Siqueira

Long-term Improvement after the Athens Protocol for Advanced Keratoconus with Significant Ectasia Progression in the Fellow Eye

[Year:2014] [Month:January-April] [Volumn:3 ] [Number:1] [Pages:51] [Pages No:40-43][No of Hits : 2143]


ABSTRACT

To describe the long-term result of the Athens protocol (custom topography-guided advanced surface ablation followed by riboflavin-UVA collagen cross-linking in the same day) for progressive advanced keratoconus in the left eye, while the fellow right eye first presented with relatively mild keratoconus that was treated with a more conservative therapeutic approach of continuous contact lenses use with the goal for ectasia stabilization. Five years after the Athens protocol, a regression of over 10D (diopters) was observed on the sagittal curvature with significant regularization of corneal shape and improvement of distance corrected visual acuity (DCVA) in the left eye. The right eye, which was treated more conservatively, had an over 12 D increase on sagittal curvature along with significant distortion of the corneal shape and reduction of DCVA.

Keywords: Keratoconus, Athens protocol, Contact lens.

How to cite this article: Pereira LC, Siqueira R, Valbon B, Santos R, Dawson D, Ambrósio R, Siqueira JA. Long-term Improvement after the Athens Protocol for Advanced Keratoconus with Significant Ectasia Progression in the Fellow Eye. Int J Kerat Ect Cor Dis 2014;3(1):40-43.

Source of support: Nil

Conflict of interest: None declared


 
Original Article
Ramez Barbara, Ali Nassar, David Zadok, Adel Barbara

Corneal Biomechanical Properties Post-LASEK for the Correction of Myopia

[Year:2014] [Month:January-April] [Volumn:3 ] [Number:1] [Pages:51] [Pages No:23-28][No of Hits : 1923]


ABSTRACT

Introduction: Laser surgeries are effective and safe, however, over the years data has accumulated about several complications of the procedures, particularly corneal ectasia. Various studies demonstrated the importance of the front layers of the cornea to keep its structure fixed. In order to correct various degrees of myopia, different thicknesses of tissue have to be removed. Therefore, it is conceivable that the risk of developing ectasia might increase depending on the depth of corneal tissue removed.
In the last few years, the Reichert Ocular Respond Analyzer (ORA) for measuring the biomechanical parameters of the cornea has been introduced. Studies demonstrated a decrease in the corneal biomechanical parameters after Laser Assisted Sub-Epithelial Keratomileusis (LASEK) surgery. However, the, relation between the depth of tissue removed and the amount of change in the biomechanical parameters had not been tested yet.

Purpose: To evaluate the relationship between corneal biomechanical parameters and corneal tissue ablation thickness.

Methods: Data was retrospectively collected from patient's files that underwent LASEK in private medical center - Hadassah Optimal in Haifa between January 2009 and May 2010. All patients were operated by same surgeon (AB). In our study we included patients that had at least three ORA measurements at three set periods of time; before the operation, up to 3 months postoperative and more than 3 months postoperative. We divided the patients into 3 groups depending on the refractive error and tested the effect of variable factors (Age, Total depth ablated-TDA, percent of total depth ablated-%TDA, sex, refraction). The data was analyzed by descriptive statistics and student t-test to find the relation between LASEK and the corneal biomechanical parameters.

Results: Ninety-eight patients participated in our study, which included 98 separate eye operations. A statistically significant decrease (p < 0.001) was found in CRF, CH, IOPg after LASEK. In group 1 (refraction -0.5 to -2.99): on CH - there was a statistically significant (p < 0.05) weak-moderate effect of TDA and %TDA (Pearson coefficient of 0.4, 0.39 respectively), statistically significant (p < 0.05) effect of age. On CRF — we found a statistically significant (p < 0.05) weak-moderate effect of TDA and %TDA (Pearson coefficient of 0.36 for both factors), statistically significant (p < 0.05) effect of age. In the second group (refraction value -3 to -5.99) only on IOPg a statistically significant (p < 0.05) weak effect of TDA (Pearson coefficient of 0.33) was demonstrated. In the third group, we did not find any effect of the variable factors on the change in biomechanical properties characteristics after LASEK.

Importance: Corneal biomechanical properties influence corneal behavior in certain eye diseases. Moreover, it has been noted that operations and procedures affect these biomechanical properties of the cornea. Hence, it is of great importance to reveal factors that could affect and change such parameters.

Keywords: Lasek , Corneal biomechanics, Corneal hysteresis, Corneal resistance factor, Pachymetry, Corneal thickness, Intraocular pressure, Laser, Cornea.

How to cite this article: Barbara R, Nassar A, Zadok D, Barbara A. Corneal Biomechanical Properties Post-LASEK for the Correction of Myopia. Int J Kerat Ect Cor Dis 2014;3(1):23-28.

Source of support: Nil

Conflict of interest: None


 
Original Article
Renato Ambrosio Jr, Michael W Belin, Victor L Perez, Juan Carlos Abad, Jose Alvaro P Gomes

Definitions and Concepts on Keratoconus and Ectatic Corneal Diseases: Panamerican Delphi Consensus - A Pilot for the Global Consensus on Ectasias

[Year:2014] [Month:September-December] [Volumn:3 ] [Number:3] [Pages:60] [Pages No:99-106][No of Hits : 1863]


ABSTRACT

Purpose: To establish consensus on definitions and concepts of keratoconus and ectatic corneal diseases by using Delphi approach.

Materials and methods: Seventeen Latin American experts on keratoconus and ectatic corneal diseases participated in a 3-round Delphi panel approach. A web-based 12 question survey was answered by panelists in two rounds, followed by life discussion meeting. A two-third majority strategy was defined as a consensus.

Results: Corneal ectatic diseases were defined as progressive thinning conditions without acute stromal inflammation, and were classified as keratoconus, pellucid marginal degeneration (PMD), keratoglobus, and ectasia after trauma or surgery. The pattern of thinning was considered the main aspect for the classification of ectatic diseases, but criteria for staging the disease needs to be improved. Corneal tomography with 3D reconstruction, distinguished from Placido-disk based front surface topography was elected as the diagnostic procedure currently capable of detecting the earliest clinical ectatic changes. Biomechanical alterations were considered to be the first event for ectasia development. Eye rubbing was directly related to the development and progression of ectasia. Inflammation was considered as a possible event on the physiopathology. Keratoconus was considered as a bilateral disease, with often asymmetric presentation, while ectasia may occur unilaterally if there is significant corneal insult, leading to biomechanical failure. No consensus was achieved for the definitions on forme fruste keratoconus (FFKC).

Conclusion: Consensus was achieved on definitions of corneal ectatic diseases. Disease staging, including criteria for FFKC or subclinical ectasia remains controversial. A larger consensus including experts from different groups around the world is needed.

Keywords: Keratoconus, Ectasia, Delphi, Questionnaires, Consensus.

How to cite this article: Ambrósio R Jr, Belin MW, Perez VL, Abad JC, Gomes JAP. Definitions and Concepts on Keratoconus and Ectatic Corneal Diseases: Panamerican Delphi Consensus - A Pilot for the Global Consensus on Ectasias. Int J Kerat Ect Cor Dis 2014;3(3):99-106.

Source of support: This work was performed by the PanCone Study Group, affiliated with PanCornea PAAO.

Conflict of interest: None


 
Original Article
Khosrow Jadidi, Seyed Aliasghar Mosavi, Farhad Nejat, Aliagha Alishiri

Complications of Intrastromal Corneal Ring Implantation (Keraring 355°) using a Femtosecond Laser for Channel Creation

[Year:2014] [Month:May-August] [Volumn:3 ] [Number:2] [Pages:46] [Pages No:53-56][No of Hits : 1860]


ABSTRACT

Purpose: To report complications after the implantation of Keraring 355° intrastromal corneal ring (ICR; Mediphacos, Belo Horizonte, Brazil) in keratoconic eyes using a Ziemer LDV femtosecond laser (Ziemer AG, Switzerland) for channel creation.

Materials and methods: Five eyes suffering from keratoconus underwent Keraring 355° insertion using Ziemer LDV for corneal pocket creation. Intraoperative and postoperative complications were recorded.

Results: While intraoperatively there were no complication, postoperatively all cases showed severe side effects.

Conclusion: In this small case series, intracorneal ring (Keraring 355°) implantation using a femtosecond laser for channel creation was related to a number of significant postoperative problems in all cases. The most common complication was corneal melting (postoperatively).

Keywords: Femtosecond laser-intrastromal corneal ring, Keraring 355°, Keratoconus-complication.

How to cite this article: Jadidi K, Mosavi SA, Nejat F, Alishiri A. Complications of Intrastromal Corneal Ring Implantation (Keraring 355°) using a Femtosecond Laser for Channel Creation. Int J Kerat Ect Cor Dis 2014;3(2):53-56.

Source of support: Nil

Conflict of interest: None declared


 
Review Article
Adel Barbara, Ramez Barbara

How to improve Visual Acuity after Intrastromal Corneal Ring Segments? Implantation for Keratoconus and Post-LASIK Ectasia

[Year:2014] [Month:May-August] [Volumn:3 ] [Number:2] [Pages:46] [Pages No:69-75][No of Hits : 1643]


ABSTRACT

Keratoconus (KC) is an ecstatic corneal disease that causes irregular astigmatism which cannot be corrected by glasses, the irregular astigmatism causes loss of visual acuity (VA) both the uncorrected and the corrected VA, in addition to deterioration in the quality of vision. Contact lenses (CLs) improve the VA but cannot be tolerated in many cases due to several causes, such as loss of motivation, atopic and allergic conjunctivitis that are more frequently associated with KC and dry eyes. Intrastromal corneal ring segments implanted in keratoconic eyes improve uncorrected visual acuity (UCVA), best spectacle corrected visual acuity (BSCVA), reduce myopia, astigmatism, high order aberrations (HOA) and regularizes the cornea (less irregular astigmatism), similar results are achieved in the treatment of post-LASIK and post PRK ectasia. These results were confirmed in long-term follow-up. The more advanced the KC the more is the effect of the ICRS but the less the functional VA achieved and vice versa. Thicker rings are more effective, and the smaller the optical zone the more is the effect of the ICRS. The aim of ICRS implantation in KC is not to be free of glasses or CL but to enable the patient of seeing with glasses or to tolerate CL in order to prevent or delay the need for penetrating keratoplasty (PKP) or deep anterior lamellar keratoplasty (DALK). In many cases, we can achieve a functional and satisfactory UCVA with no need for glasses and this is the case in nonadvanced KC but not in the advanced cases. In some cases, the results achieved need additional means to improve VA in order to get satisfactory VA. There are nonsurgical and surgical means to improve VA after ICRS, these means will be reviewed in this article.

Keywords: Keratoconus, Intrastromal, Cornea, Rings, Intacs, Ferrara rings, Penetrating keratoplasty, Deep lamellar keratoplasty, Collagen, Cross-linking, PRK, Lasik, Ectasia.

How to cite this article: Barbara A, Barbara R. How to improve Visual Acuity after Intrastromal Corneal Ring Segments? Implantation for Keratoconus and Post-LASIK Ectasia. Int J Kerat Ect Cor Dis 2014;3(2):69-75.

Source of support: Nil

Conflict of interest: None declared


 
Original Article
Albert Daxer

Biomechanics of the Cornea

[Year:2014] [Month:May-August] [Volumn:3 ] [Number:2] [Pages:46] [Pages No:57-62][No of Hits : 1557]


ABSTRACT

The purpose of this article is to provide an applicable and easy-to-use mathematical model of the biomechanics of the cornea. The new spherical dome model considers not only the heterogeneity of the tunica of the eye and distinguishes structurally between cornea, limbus and sclera. It also implements the structural anisotropy inside the corneal stroma caused by the corneas lamellar structure as well as the asphericity of the corneal shape.

Keywords: Cornea, Biomechanics, Corneal stress, Corneal model, LASIK, LASEK, PRK, SMILE, Keratectasia, Spherical dome model.

How to cite this article: Daxer A. Biomechanics of the Cornea. Int J Kerat Ect Cor Dis 2014;3(2):57-62.

Source of support: Nil

Conflict of interest: None


 
Review Article
Elizabeth Hawkes, Mayank A Nanavaty

Eye Rubbing and Keratoconus: A Literature Review

[Year:2014] [Month:September-December] [Volumn:3 ] [Number:3] [Pages:60] [Pages No:118-121][No of Hits : 1522]


ABSTRACT

Keratoconus is a progressive corneal ectactic condition that can lead to visual loss. Despite being the most common cause for keratoplasty in the developed world the aetiology is unknown. It is thought to be multifactorial, with genetic and environmental factors implicated. The association of eye rubbing and pathogenesis of keratoconus has been well documented. In this review, we collate the existing literature and summarize the current knowledge of the role of eye rubbing in the pathogenesis of keratoconus.

Keywords: Keratoconus, Eye rubbing, Corneal ectasia.

How to cite this article: Hawkes E, Nanavaty MA. Eye Rubbing and Keratoconus: A Literature Review. Int J Kerat Ect Cor Dis 2014;3(3):118-121.

Source of support: Nil

Conflict of interest: None


 
Original Article
Hassenien Safa Shuber

Implantable Collamer Lens for Correction of Refractive Errors in Patients with Keratoconus following Collagen Cross-Linking: One Year Follow-up

[Year:2014] [Month:January-April] [Volumn:3 ] [Number:1] [Pages:51] [Pages No:29-35][No of Hits : 1333]


ABSTRACT

Objective: The purpose of this study is to assess the predictability, safety, efficacy and stability of correction of refractive errors in patients with keratoconus using Visian implantable collamer lens (ICL) following collagen cross-linking.

Materials and methods: This prospective, non-comparative study evaluated 20 eyes of 14 patients with keratoconus subjected to implantation of intraocular collamer lens at least 1 year following collagen cross-linking and stable refraction. Mean preoperative myopia was -8.43 ± 5.13 Diopters (D) (-3.5 to -20.0D and mean cylinder was -2.19 ± 1.28D (0.0 to -4.5D). The preoperative spherical equivalent (SE) was -9.52 ± 5.33D (-3.75 to -21.25D). During the 12 months follow-up, uncorrected visual acuity, best corrected visual acuity, refraction, intraocular pressure and vaulting are measured.

Results: At 12 months postoperatively, 90% of eye had refractive cylinder of <1.0D with (p = 0.003) and 20 (100%) eyes was within ±0.75D of sphere at 1 year (r2 = 0.99) and (p = 0.0085). The mean postoperative BCVA in decimal was 0.498 ± 0.232, while the mean preoperative BCVA was 0.484 ± 0.285. The safety index at 12 months was 1.02. The mean postoperative UCVA in decimal was 0.498 ± 0.232 and the mean preoperative BCVA is 0.484 ± 0.29 and the efficacy index at 12 months was 1.01.

Conclusion: Implantation of Visian Intraocular collamer lens is predictable, safe and effective way to correct refractive error in patients with keratoconus following collagen cross-linking.

Keywords: Keratoconus, Intraocular collamer lens, Collagen cross linking.

How to cite this article: Shuber HS. Implantable Collamer Lens for Correction of Refractive Errors in Patients with Keratoconus following Collagen Cross-Linking: One Year Follow-up. Int J Kerat Ect Cor Dis 2014;3(1):29-35.

Source of support: Nil

Conflict of interest: None


 
Case Report
Marouen Berguiga, Alain Saad, Damien Gatinel

Unilateral Post-Lasik Ectasia in a Topographical Normal Eye with a Slight Asymmetry in the Contralateral Eye

[Year:2014] [Month:January-April] [Volumn:3 ] [Number:1] [Pages:51] [Pages No:47-51][No of Hits : 1331]


ABSTRACT

Purpose: To report a case of post-lasik unilateral corneal ectasia.

Setting: Department of Anterior Segment and Refractive Surgery, Rothschild Foundation, Paris.

Case report: A 33-year-old woman was referred with a history of unilateral post-Lasik ectasia in her left eye, 18 months post operatively. Her best-corrected visual acuity was 20/20 with a manifest refraction of +1.75 (–4.75 × 90). Orbscan II® revealed an inferior steepening associated with irregular astigmatism. The preoperative Placido topographies revealed a slight skewed radial axis in the right eye associated with an inferior-superior keratometry difference of 1.6 Diopters at 3 mm. In the left eye that developed ectasia, regular symmetric astigmatism was present. Uncorrected visual acuity improved to 20/25 2 weeks after KeraRing® segment insertion.

Keywords: LASIK, Ectasia, Intrastromal corneal ring segments, Femtosecond.

How to cite this article: Berguiga M, Saad A, Gatinel D. Unilateral Post-Lasik Ectasia in a Topographical Normal Eye with a Slight Asymmetry in the Contralateral Eye. Int J Kerat Ect Cor Dis 2014;3(1):47-51.

Source of support: Nil

Conflict of interest: None declared


 
Case Series
Ramez Barbara, Adel Barbara

Intrastromal Corneal Ring Segment with and without Collagen Corneal Crosslinking vs Penetrating Keratoplasty for the Treatment of Keratoconus

[Year:2014] [Month:May-August] [Volumn:3 ] [Number:2] [Pages:46] [Pages No:88-94][No of Hits : 1188]


ABSTRACT

Keratoconus (KC) is a noninflammatory progressive corneal degeneration that cause irregular astigmatism especially in moderate and advanced cases, the irregular astigmatism can not be corrected by glasses, contact lenses are the only optical way for improving the visual acuity (VA) in these patients. In this retrospective study, we shall present the results of eight patients suffering from KC who were treated by PKP in one eye (PKP group) and ICRS (ICRS group) with or without CXL in the second eye. All the ICRS surgeries, the CXL and the PRK were performed at the I Vision, Refractive Surgery and Keratoconus Treatment Center in Haifa, Israel, by the same surgeon (AB), the PKPs were performed elsewhere, because they were treated in our medical center after the PKP.

Keywords: Keratoconus, Intrastromal, Cornea, Rings, Intacs, Ferrara rings, Penetrating keratoplasty, Deep lamellar keratoplasty, Collagen, Cross-linking.

How to cite this article: Barbara R, Barbara A. Intrastromal Corneal Ring Segment with and without Collagen Corneal Crosslinking vs Penetrating Keratoplasty for the Treatment of Keratoconus. Int J Kerat Ect Cor Dis 2014;3(2):88-94.

Source of support: Nil

Conflict of interest: None declared


 
Presentation
Ramez Barbara

Presentation on Keratoconus Expert Meeting, London, 2014

[Year:2014] [Month:September-December] [Volumn:3 ] [Number:3] [Pages:60] [Pages No:141-158][No of Hits : 1132]



 
Original Article
PS David O’Brart, Parul Patel, Naomi A O’Brart

Five Years Follow-up of Riboflavin/Ultraviolet A (370 nm) Corneal Collagen Cross-linking to Halt the Progression of Keratoconus

[Year:2014] [Month:May-August] [Volumn:3 ] [Number:2] [Pages:46] [Pages No:63-68][No of Hits : 1130]


ABSTRACT

Aims: To determine the long-term efficacy and safety of riboflavin/ultraviolet a corneal cross-linking (CXL) to halt the progression of keratoconus.

Materials and methods: Thirty-five patients (35 eyes) who had undergone CXL with epithelial removal 5 or more years previously were examined.

Results: At 5 years, mean spherical equivalent (SEQ) increased by 0.78 diopters (D) (p < 0.001), mean simulated K (Sim K) reduced by 0.86D (p < 0.00001), cone apex power (CAP) reduced by 1.1D (p < 0.0002) and root mean square (RMS) (p < 0.0001), coma (p < 0.0001), and secondary astigmatism (p < 0.001) decreased compared to preoperative values. Compared to values at 1 year, mean refractive cylinder reduced by 0.26D (p < 0.05), mean Sim K reduced by 0.46D (p < 0.0005), CAP reduced by 0.81D (p < 0.01), RMS (p < 0.001), coma (p < 0.002) and secondary astigmatism (p < 0.02) reduced and central pachymetry increased (p < 0.05) at 5 years. No treated eyes showed evidence of progression at 5 years. None lost >1 line of CDVA. Eight untreated fellow eyes progressed during the follow-up period and underwent CXL.

Conclusions: Corneal cross-linking is an effective treatment to halt the progression of keratoconus at 5 years, with no sight-threatening complications. Improvements in topographic and wave-front indices present at 1 year continue to improve at 5 years.

Keywords: Keratoconus, Cross-linkage, Riboflavin, Ultraviolet light.

How to cite this article: O’Brart PSD, Patel P, O’Brart NA. Five Years Follow-up of Riboflavin/Ultraviolet A (370 nm) Corneal Collagen Cross-linking to Halt the Progression of Keratoconus. Int J Kerat Ect Cor Dis 2014;3(2):63-68.

Source of support: Nil

Conflict of interest: None


 
Case Report
Raquel Almeida, Filipa Rodrigues, Matheus Santos, Renata Siqueira, Patrícia Contarini, Jose Salgado-Borges, Renato Ambrosio Jr

Corneal Thinning after Contact Lens-related Infective Keratitis

[Year:2014] [Month:May-August] [Volumn:3 ] [Number:2] [Pages:46] [Pages No:95-98][No of Hits : 1042]


ABSTRACT

Purpose: To describe two cases of contact lens-related infectious keratitis with secondary corneal thinning.

Material and methods: Case reports and review of the literature.

Results: The first case is of a 13-year-old girl, contact lens user, admitted for acute corneal infection in her right eye (OD). Seven years after treatment, she presented with corneal thinning and flattening with uncorrected distance visual acuity of 20/30 OD; thinnest value was 363 µm in OD and 513 µm in the left eye (OS). The second case is a 22-year-old male, cosmetic contact lens user, first presented with severe keratitis in OD. One year after treatment, the eye was quiet with moderate corneal opacity; corneal thickness was 228 µm OD and 561 µm OS. Ectasia was identified due to the protrusion and steepening with an irregular curvature pattern. Rigid gas permeable (RGP) contact lens fitting enabled visual acuity of 20/25 OD.

Conclusion: Corneal melt with secondary stromal loss and thinning may lead or not to secondary ectasia. Visual rehabilitation is possible with RGP contact lenses despite corneal opacity. The risk of infectious keratitis among contact lenses users should be considered.

Keywords: Corneal ulcers, Ectasia, Contact lenses.

How to cite this article: Almeida R, Rodrigues F, Santos M, Siqueira R, Contarini P, Salgado-Borges J, Ambrosio R Jr. Corneal Thinning after Contact Lens-related Infective Keratitis. Int J Kerat Ect Cor Dis 2014;3(2):95-98.

Source of support: Nil

Conflict of interest: None declared


 
Case Report
Guilherme Rocha, Leonardo Torquetti, Arthur Rocha

Transient Keratoconus following Acute Conjunctivitis

[Year:2014] [Month:September-December] [Volumn:3 ] [Number:3] [Pages:60] [Pages No:136-140][No of Hits : 1012]


ABSTRACT

A 34-year-old female patient presented low visual acuity and vision fluctuation in left eye after a referred acute conjunctivitis. Two previous ophthalmological evaluations diagnosed keratoconus, but the patient disagreed with this diagnosis. Following the patient with an anterior segment tomography and clinical evaluation showed that she had a keratoconuslike topographic and clinical pattern that resolved after a few months of follow-up.

Keywords: Keratoconus, Eye rubbing/keratoconus, Inflammatory processes/keratoconus, Corneal topography, Epidemiology/ keratoconus.

How to cite this article: Rocha G, Torquetti L, Rocha A. Transient Keratoconus following Acute Conjunctivitis. Int J Kerat Ect Cor Dis 2014;3(3):136-140.

Source of support: Nil

Conflict of interest: None


 
Retrospective Study
Erez Bakshi, Irina S Barequet, Isaac Aizenman, Samuel Levinger, Isaac Avni, David Zadok

Corneal Cross-linking in Patients Younger than 18 Years: Long-term Follow-up in Three Israeli Medical Centers

[Year:2014] [Month:May-August] [Volumn:3 ] [Number:2] [Pages:46] [Pages No:84-87][No of Hits : 968]


ABSTRACT

Purpose: To report refractive, topographic and safety outcomes of corneal cross-linking (CXL) in patients younger than 18 years of age with progressive keratoconus.

Materials and methods: In this retrospective study, we enrolled 31 eyes of 21 children aged 11 to 17 years that underwent corneal riboflavin-ultraviolet A induced CXL due to progressive keratoconus at three different ophthalmology departments in Israel. They were followed for 3 to 48 months (average 23 ± 13.6 months). Evaluated parameters were uncorrected visual acuity (UCVA), best spectacle corrected visual acuity (BSCVA), manifest refraction, pachymetry, slit- lamp examination and corneal topography at baseline and at 1,3,6,12,24 and 48 months.

Results: We found a nonsignificant improvement in UCVA and BSCVA with a small reduction of manifest cylinder and no significant change in spherical equivalent or K-values. Following CXL, stability of UCVA and BSCVA at the last follow-up examination was found in 71 and 77% of treated eyes, respectively. No permanent adverse events have been recorded throughout the study period.

Conclusion: In our series, CXL was a safe procedure in the pediatric population. Stabilization of progressive keratoconus was achieved in visual acuity, refractive and topography parameters with no improvement in corneal indices in contrary to adult CXL treatment.

Keywords: Progressive keratoconus, Collagen cross-linking, Riboflavin, UVA irradiation, Pediatric.

How to cite this article: Bakshi E, Barequet IS, Aizenman I, Levinger S, Avni I, Zadok D. Corneal Corss-linking in Patients Younger than 18 Years: Long-term Follow-up in Three Israeli Medical Centers. Int J Kerat Ect Cor Dis 2014;3(2):84-87.

Source of support: Nil

Conflict of interest: None declared


 
Editorial
A John Kanellopoulos

KANELLOPOULOS-KERATOCONUS DIAGNOSIS AND TREATMENT, 2014

[Year:2014] [Month:May-August] [Volumn:3 ] [Number:2] [Pages:46] [Pages No:v-xi][No of Hits : 955]


ABSTRACT

KANELLOPOULOS-KERATOCONUS DIAGNOSIS AND TREATMENT, 2014

A Few Thoughts, Unanswered Questions and Hopes in regard to Keratoconus Diagnosis and Treatment

As the corneal collagen cross-linking (CXL) treatment is intended to be applied in eyes developing progressive ectasia, it is of paramount importance the establishment of early and sensitive criteria for the diagnosis of keratoconus as well as the establishment of possible progression.


 
Case Series
Pablo F Rodrigues, Guilherme Ferrara, Paulo Ferrara, Wagner G Dias, Leonardo Torquetti

Intrastromal Corneal Ring Segments Implantation in Patients with Mild Keratoconus

[Year:2014] [Month:September-December] [Volumn:3 ] [Number:3] [Pages:60] [Pages No:122-126][No of Hits : 943]


ABSTRACT

Purpose: The purpose of this study is to evaluate the topographic, topometric and visual changes after implantation of Ferrara intrastromal corneal ring segments (ICRS) in grades I and II keratoconus patients.

Materials and methods: The chart records of 50 consecutively operated keratoconus patients were reviewed. The patients were operated on by the same surgeon, with the manual technique. All patients were preoperatively and postoperatively evaluated with the Pentacam (OCULUS Optikgeräte, Wetzlar, Germany). The studied parameters were: uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), keratometry, corneal asphericity and corneal volume.

Results: Fifty eyes of 42 patients (26 males and 16 females) were analyzed. The mean preoperative UDVA was 0.91 ranging from LogMAR 0.10 to 1.30. The mean postoperative CDVA was 0.19 ranging from 0.00 to 0.54 LogMAR. The postoperative CDVA was equal or better than 0.18 in 37 cases (74%). The mean K1 decreased from 45.80D (±2.52) preoperatively to 44.27D (± 2.10) postoperatively and the mean K2 value, from 49.06D (± 2.09) to 46.22D (±1.89). The mean asphericity increased from ?0.71 preoperatively to ?0.29 postoperatively. The average preoperative corneal volume was 56.89 ± 3.11 mm3 while the average postoperative corneal volume was 57.64 ± 3.05 mm3.

Conclusion: The study supports the early indication of implantation of Ferrara ICRS in mild to moderate keratoconus cases in order to achieve good visual, keratometric and ashpericity outcomes.

Keywords: Mild keratoconus, Intrastromal corneal ring segment, Corneal volume, Asphericity.

How to cite this article: Rodrigues PF, Ferrara G, Ferrara P, Dias WG, Torquetti L. Intrastromal Corneal Ring Segments Implantation in Patients with Mild Keratoconus. Int J Kerat Ect Cor Dis 2014;3(3):122-126.

Source of support: Nil

Conflict of interest: None


 
Case Report
Jose M Gonzalez-Meijome, Sofia C Peixoto-de-Matos, Anabela Soares, Antonio Queiros, Alberto Diaz-Rey, Jose Salgado-Borges

Topographical Irregularity and Keratoconic Findings in Five Siblings and their Parents

[Year:2014] [Month:September-December] [Volumn:3 ] [Number:3] [Pages:60] [Pages No:130-135][No of Hits : 904]


ABSTRACT

Purpose: To report the clinical features of five siblings, four of them with positive diagnostic of keratoconus in different degrees of severity as well as their parents findings.

Materials and methods: Seven elements of the same family, five young siblings (2 males, 3 females), and their parents were screened for potential keratoconic signs. Topographic data from 60 normal eyes are also reported for comparison purposes. Complete ophthalmologic examination including biomicroscopic, topographic and refractive examination. Main outcome measures included biomicroscopic findings, refractive error and visual acuity, simulated keratometry, corneal eccentricity, indices of asymmetry and regularity.

Results: The more advanced case was present in the left eye of a male member, needing a rigid gas permeable lens to correct irregular astigmatism. Another brother also presented bilateral mild to moderate keratoconus with no apparent vision complaints. The third case diagnosed was one sister with history of monthly disposable soft toric lens to compensate a presumed initially regular astigmatism two years before. The remaining two cases being the older sister and one of the younger sisters presented the less noticeable signs, with confirmation of the pathology only in one of them and warranting a close followup of both due to the asymmetric corneal topography between both eyes as well as between the flatter superior and steeper inferior corneal areas.

Conclusion: This is the first reported case series involving diagnosis of keratoconus or atypical corneal topographies in several young siblings and their parents. Further evaluation of this and other cases with similar presentations might help to gain a deeper understanding on the potential genetic paths of keratoconus.

Keywords: Keratoconus, Family, Genetics, Corneal topography.

How to cite this article: González-Méijome JM, Peixoto-de- Matos SC, Soares A, Queirós A, Díaz-Rey A, Salgado-Borges J. Topographical Irregularity and Keratoconic Findings in Five Siblings and their Parents. Int J Kerat Ect Cor Dis 2014;3(3): 130-135.

Source of support: Nil

Conflict of interest: None


 
Editorial
Adel Barbara

Editorial

[Year:2014] [Month:January-April] [Volumn:3 ] [Number:1] [Pages:51] [Pages No:v][No of Hits : 900]


Editorial

I am delighted to present the 7th issue of the International Journal of Keratoconus and Ectatic Corneal Diseases. Indeed, we have completed 2 years of publishing in this journal, accounting for six issues, and here we are in our 3rd year.


 
Case Report
Boris Severinsky

Silicone Hydrogel Miniscleral Contact Lenses after Corneal Collagen Crosslinking for Post-LASIK Keratoectasia

[Year:2014] [Month:September-December] [Volumn:3 ] [Number:3] [Pages:60] [Pages No:127-129][No of Hits : 862]


ABSTRACT

Purpose: To report successful visual rehabilitation of post refractive surgery keratoectasia shortly after corneal collage crosslinking (CXL) procedure achieved with silicone hydrogel mini-scleral (SHmS) contact lens.

Materials and methods: A 29-year-old woman attended to our clinic with complaints on decreased vision in her left eye. Twelve years earlier she underwent bilateral laser-assisted in situ keratomileusis (LASIK) procedure for myopia correction. Corneal topography revealed bilateral central keratoectasia with maximal keratometry values of 55.4 Diopter (D) for her right eye and 59.7 D for the left, corneal thicknesses were 422 and 443 respectively. The patient underwent an uneventful CXL procedure in her left eye and was fitted with SHmS lens 5 weeks later. The lens was designed to rest over the patients’ sclera and perilimbal cornea and vault the central cornea with minimal support over it.

Results: SHmS lens fitting resulted in significant subjective improvement in visual acuity (from 20/200, unaided to 20/25, contact lens corrected). The patient was able to wear the lens upto 10 hours a day with stable contact lens corrected vision. No contact lens related complications, such as edema or neovascularization were observed during 3 months follow-up period. As a result of successful restoration of vision in the CXL-treated eye, the patient was scheduled for the procedure in her other eye.

Conclusion: SHmS contact lens should be considered as an option for the visual rehabilitation of corneas shortly after collagen corneal crosslinking procedure. This novel contact lens modality made from flexible and highly gas permeable material minimizes contact lens influence on corneal recovery after CXL and provides an excellent visual outcome.

Keywords: Keratoconus, Corneal collagen crosslinking, Custom soft contact lenses.

How to cite this article: Severinsky B. Silicone Hydrogel Miniscleral Contact Lenses after Corneal Collagen Crosslinking for Post-LASIK Keratoectasia. Int J Kerat Ect Cor Dis 2014;3(3): 127-129.

Source of support: Nil

Conflict of interest: None


 
Original Article
Adam Muzychuk, Victor Penner, Guillermo Rocha

High Order Aberration Outcomes of Corneal Collagen Crosslinking in Eyes with Keratoconus and Post-LASIK Ectasia

[Year:2014] [Month:September-December] [Volumn:3 ] [Number:3] [Pages:60] [Pages No:107-112][No of Hits : 691]


ABSTRACT

Purpose: To evaluate the effect of riboflavin and ultraviolet- A-induced corneal collagen crosslinking (CXL) on high order aberrations (HOA) up to third-order at 6 months using the iTrace wavefront aberrometer in patients with progressive keratoconus and post-LASIK ectasia.

Materials and methods: Ongoing retrospective chart review of patients having undergone CXL. The iTrace (Tracey Technologies, Houston, TX) was used to evaluate HOA. Patient data was collected from a single clinical site pre- and 6 months postoperatively. Data collected included logMAR uncorrected distance visual acuity (UDVA), logMAR corrected distance visual acuity (CDVA), manifest refraction, and HOA measurements. Data was analyzed with paired two-tailed student’s t-test.