Epithelial Basement Membrane Dystrophy Research Articles

Transepithelial phototherapeutic keratectomy for treatment-resistant recurrent corneal erosion syndrome.

To evaluate the efficacy and safety of trans-epithelial phototherapeutic keratectomy (TE-PTK) as a treatment for recurrent corneal erosion syndrome (RCES) in patients with symptoms refractory to conventional treatments. All patients who received TE-PTK treatment for RCES had failed 3 or more conventional treatments and were reviewed, and if met criteria, approved by healthcare workers of the British Columbia public health authority (Medical Services Plan (MSP). A retrospective chart review and telephone survey were conducted at the Pacific Laser Eye Centre (PLEC). Exclusion criteria were ocular co-morbidities potentially affecting treatment efficacy. This study included 593 eyes of 555 patients (46.2% male; 50.9 ± 14.2years old) who underwent TE-PTK. The leading identified causes of RCES were trauma (45.7%) and anterior basement membrane dystrophy (44.2%). The most common pre-PTK interventions were ocular lubricants (90.9%), hypertonic solutions (77.9%), and bandage contact lenses (50.9%). Thirty-six eyes had undergone surgical interventions such as stromal puncture, epithelial debridement, or diamond burr polishing. Post-PTK, 78% of patients did not require any subsequent therapies and 20% required ongoing drops. Six patients (1.1%) reported no symptom improvement and required repeat TE-PTK for ongoing RCES symptoms after initial TE-PTK. All 6 eyes were successfully retreated with TE-PTK (average time to retreatment was 11.3 ± 14.9months). There was no significant difference in best corrected visual acuity pre- vs. post-operatively. The mean post-operative follow-up was 60.5months (range: 5-127months). TE-PTK has a good efficacy and safety profile for treatment-resistant RCES. The third-party public health-reviewed nature of this study, the low recurrence rate of RCES, and the low PTK retreatment rate suggest that TE-PTK might be considered for wider use in the management of RCES.

Clinical outcomes of epithelial basement membrane dystrophy after keratorefractive lenticule extraction.

To determine the clinical outcomes of keratorefractive lenticule extraction (KLEx) in eyes with epithelial basement membrane dystrophy (EBMD) that developed after surgery. Onnuri Smile Eye Clinic, Seoul, South Korea. Retrospective single-center study. This study reviewed the medical records of 26 eyes of 16 patients who exhibited signs of EBMD after KLEx. Postoperatively, corneal findings and visual outcomes were evaluated. Statistical analyses were also performed on eyes without corneal complications after KLEx. Signs of EBMD were first observed within 1 week postoperatively in 22 eyes (84.6%): 6 eyes (23.1%) showed epithelial defects, 10 eyes (38.5%) showed subepithelial corneal opacity, 5 eyes (19.2%) showed diffuse lamellar keratitis, and 1 eye (3.9%) showed epithelial ingrowth. Symptoms such as pain, while corneal lesions were present, occurred in 21 eyes (80.8%). At 3 months postoperatively, 21 eyes (80.8%) showed no specific findings on slitlamp microscopy after medical treatment, 2 eyes (7.7%) showed subepithelial corneal opacity, 2 eyes (7.7%) showed corneal scar, and 1 eye (3.9%) showed epithelial ingrowth. Uncorrected distance visual acuity was 20/25 or better in 24 eyes (92.3%), and spherical equivalent was within ±1.0 D in 20 eyes (76.9%). The efficacy index of the EBMD group did not significantly differ from the control group, while the safety index was significantly lower. Manifestations of EBMD can occur after KLEx and can affect clinical outcomes. Most cases showed favorable results with appropriate nonsurgical treatment; however, some cases had long-term complications such as corneal scarring.

Matrix Metalloproteinases and the Pathogenesis of Recurrent Corneal Erosions and Epithelial Basement Membrane Dystrophy.

Matrix metalloproteinases (MMPs) are a group of proteolytic enzymes which are members of the zinc endopeptidase family. They have the ability to degrade extracellular matrix elements, allowing for the release of binding molecules and cell migration. Although metalloproteinases regulate numerous physiological processes within the cornea, overexpression of metalloproteinase genes and an imbalance between the levels of metalloproteinases and their inhibitors can contribute to the inhibition of repair processes, the development of inflammation and excessive cellular proliferation. The involvement of MMPs in the pathogenesis of dystrophic corneal diseases needs clarification. Our analyses focus on the involvement of individual metalloproteinases in the pathogenesis of recurrent corneal erosions and highlight their impact on the development of corneal epithelial basement membrane dystrophy (EBMD). We hypothesize that abnormalities observed in patients with EBMD may result from the accumulation and activation of metalloproteinases in the basal layers of the corneal epithelium, leading to basement membrane degradation. A barrier formed from degradation materials inhibits the normal migration of epithelial cells to the superficial layers, which contributes to the development of the aforementioned lesions. This hypothesis seems to be lent support by the elevated concentrations of metalloproteinases in the corneal epithelium of these patients found in our previous studies on the relationships between MMPs and recurrent corneal erosions.

Factors Predictive of Refractive Error After Toric Lens Implantation.

To identify factors related to suboptimal refractive outcomes after toric intraocular lens implantation. A retrospective case-control chart review of 446 eyes with toric lens insertion by the same surgeon at a university hospital from 2016 to 2020 was conducted. Pre-operative exam findings, biometry, and one month and three month post-operative vision and refraction were noted. Reviewed charts were considered cases if uncorrected distance visual acuity (UDVA) was worse than 20/40, spherical equivalent (SE) >1 diopter (D) off target, or cylinder >1 D off target. Overall, 93.7% (n = 343) of eyes achieved UDVA of 20/40 or better, 92.7% (n = 306) were within 1 D of target SE, and 90.9% (n = 300) were within 1 D of target cylinder. UDVA cases had more eyes with prior LASIK (21.7% vs 7.0%, p = 0.01) and keratoconus (8.7% vs 0.6%, p < 0.001) than controls. More SE cases had prior radial keratotomy (RK) (8.3% vs 0%, p < 0.001) and keratoconus (12.5% vs 0%, p < 0.001) than controls. More cylinder cases had prior LASIK (30.0% vs 8.7%, p < 0.001) and higher mean astigmatism (2.3 vs 1.5 D, p = 0.02) than controls. More cases in all three analyses had higher toric cylinder power (T5-T9) than controls. Age, sex, eye laterality, axial length, anterior chamber depth, lens power, dry eye, anterior basement membrane dystrophy, and Fuchs' endothelial dystrophy differences were not significant. Prior LASIK or RK, keratoconus, and higher astigmatism may increase the chance of a suboptimal outcome.

Acuity and Quality of Vision in Eyes with Epithelial Basement Membrane Dystrophy after Regular Pseudophakia.

This retrospective case-control study was conducted to quantitatively and qualitatively assess the visual impairment in eyes with Epithelial Basement Membrane Dystrophy (EBMD) after regular cataract surgery. EBMD pseudophakic eyes were compared with matched pseudophakic eyes free from surface disorders. At least 3 weeks after surgery we evaluated uncorrected and best-corrected distance visual acuity (UDVA and CDVA), objective aberrometry, Point Spread Function (PSF), Modulation Transfer Function (MTF), and patient complaints. Twenty-five EBMD eyes and 25 control eyes (13 patients per group) were included. Nine patients per group had a monofocal IOL, and four patients had a trifocal IOL. All the EBMD patients complained of postoperative blurred vision with ocular discomfort; intensive use of lubricants induced subjective improvement only in eyes with monofocal IOLs. Postoperative mean UDVA was 0.19 ± 0.16 LogMAR in the EBMD eyes and 0.11 ± 0.04 LogMAR in the control group (p = 0.016). Mean CDVA was 0.18 ± 0.15 LogMAR in the EBMD eyes and 0.06 ± 0.04 LogMAR in the control eyes (p = 0.001). The PSF curve width was significantly worse in the EBMD group (p < 0.001). The MTF cut-off value was lower in the EBMD group than in the control group (p < 0.001). After cataract removal, eyes with EBMD had significantly lower UDVA and CDVA than controls. All the aberrometric parameters were significantly worse in EBMD cases. EBMD patients complained about their postoperative visual outcome, while control patients did not.

Safety and Efficacy of Hypertonic Sodium Chloride 5% Ointment for Recurrent Corneal Erosion Syndrome.

Background In this study, we aimed to assess the safety and efficacy of hypertonic sodium chloride 5% ointment in the treatment of recurrent corneal erosion syndrome (RCES). Methodology A total of 21 eyes from 21 patients with RCES either following trauma or spontaneously due to underlying anterior basement membrane dystrophy (ABMD) were prospectively enrolled over a six-month period. The acute episode was managed with topical sodium chloride 5% ophthalmic ointment applied twice daily for 30 days. Patients were followed up at one month and six months with visual acuity and endothelial cell count (ECC) measurement. Results The mean age was 44.19 years (range = 17-87 years). All patients had unilateral involvement. The etiology was ABMD in 12 cases, while nine cases were post-traumatic. The mean best-corrected visual acuity (BCVA) at presentation was 0.32 logMAR units (SD = 0.18), and the mean ECC before treatment initiation was 2,720 cells/mm2 (SD ± 192). At the one-month follow-up, all patients had a full recovery with complete re-epithelization of the defective area and resolution of symptoms. The mean BCVA was 0.05 logMAR units (SD = 0.12), and the mean ECC was 2,703 cells/mm2 (SD = 205). At six months, only one recurrence was documented following another episode of trauma. The mean BCVA and ECC at six months were 0.01 logMAR units and 2,714 cells/mm2, respectively. Conclusions Sodium chloride 5% ophthalmic ointment applied twice daily for 30 days following the acute event seems to be a safe and effective treatment option for RCES from both traumatic and ABMD etiology.

Preliminary Examination Before Cataract Surgery

To plan and execute a successful and safe cataract surgery one must conduct a structured, goal- and patient-oriented examination. The medical history provides crucial information regarding the planning of the anesthetic procedure, lens selection and possible intraoperative complications. Visual acuity and refraction measurements are essential for both documentation and discussion of the selected target refraction. Multifocal lenses have various contraindications to which attention must be paid during slit lamp examination and other imaging diagnostics. These include epithelial basement membrane dystrophy, Fuchs' endothelial dystrophy, zonular weakness, and progressive retinal diseases such as progressive AMD. Tomography reveals corneal irregularities as well as possible refractive laser treatments that have been performed previously. Lens calculation is complicated in these cases. Additionally, an endothelial cell count, aberrometry to rule out higher order aberrations, pupillometry and an analysis of the tear film can provide further information. The patient must be informed verbally about the severity of the procedure and the risks relevant for him with sufficient distance to the surgery.

Epithelial thickness mapping for corneal refractive surgery.

As more devices become available that offer corneal epithelial thickness mapping, this is becoming more widely used for numerous applications in corneal refractive surgery. The epithelial thickness profile is nonuniform in the normal eye, being thinner superiorly than inferiorly and thinner temporally than nasally. Changes in the epithelial thickness profile are highly predictable, responding to compensate for changes in the stromal curvature gradient, using the eyelid as an outer template. This leads to characteristic changes that can be used for early screening in keratoconus, postoperative monitoring for early signs of corneal ectasia, and for determining whether further steepening can be performed without the risk of apical syndrome following primary hyperopic treatment. Compensatory epithelial thickness changes are also a critical part of diagnosis in irregular astigmatism as these partially mask the stromal surface irregularities. The epithelial thickness map can then be used to plan a trans-epithelial PRK treatment for cases of irregularly irregular astigmatism. Other factors can also affect the epithelial thickness profile, including dry eye, anterior basement membrane dystrophy and eyelid ptosis. Epithelial thickness mapping is becoming a crucial tool for refractive surgery, in particular for keratoconus screening, ectasia monitoring, hyperopic treatment planning, and therapeutic diagnosis and treatment.

Phototherapeutische Keratektomie bei rezidivierenden Hornhauterosionen verschiedener epithelialer Genese: Einfluss der Ablationstiefe auf Pachymetrie und Refraktion

Phototherapeutic keratectomy (PTK) is an established treatment method for patients suffering from either genetic corneal dystrophy or recurrent corneal erosion (RCE) without underlying basement membrane dystrophy, often caused by trauma. This study aimed to describe the changes in manifest subjective refraction and pachymetry after PTK treatment in patients suffering from epithelial basement membrane dystrophy (EBMD) and traumatic or atraumatic RCE without underlying EBMD. This was aretrospective, single-center study performed at the Department of Ophthalmology of the Ludwig-Maximilians University (Munich). Patient data were retrospective collected using the smart-eye database of the Department of Ophthalmology including diagnostic data from an autorefractometer and from the Pentacam HR. All laser treatments were performed with an ablation depth of 10 μm for EBMD patients and 6 μm for RCE patients without EBMD. Both collectives showed adecrease in pachymetry larger than the calculated ablation depths after afollow-up interval of 126days (95% CI 104-147days). While the EBMD collective receiving an ablation of 10 μm showed adecrease of 25.8 μm (N = 74; 95% CI 21.2-30.3; p < 0.001), the non-EBMD collective receiving an ablation of 6 μm showed a decrease of 12.3 μm (N = 44, 95% CI 7.0-17.7; p < 0.001). Both, total corneal refractive power (TCRP) as well as spherical equivalent (SE) offered no significant change in preoperative and postoperative comparison for the EBMD collective. On the other hand, patients without underlying EBMD showed asignificant myopic decrease in SE of 0.4 dpt (±0.7 dpt SD, p < 0.05). The mean follow-up interval was 126 days (95% CI 104-147 days). PTK treatment offers an effective method for patients suffering from either EBMD dystrophy or RCE syndrome without underlying EBMD. The final ablation based on pachymetry at the apex can be estimated at 2.3 to 2.6 times higher compared to the original ablation depth. The reasons for this are on the one hand the laser ablation itself and the influence of the reactive wound healing of the corneal epithelium.

P-13 Trans-epithelial phototherapeutic keratectomy (PTK) for recurrent corneal erosion syndrome (RCES).

All patients who received PTK treatment for RCES had failed more than one conventional treatment, and were first vetted and approved by the British Columbia public health authority. A retrospective chart review and telephone survey were conducted at the Pacific Laser Eye Centre. Exclusion criteria were ocular co-morbidities potentially affecting treatment efficacy. This study included 593 eyes of 555 patients (46.2% male; 50.9±14.2 years old) who underwent PTK. The leading identified causes of RCES were trauma (45.7%) and anterior basement membrane dystrophy (44.2%). The most common pre-PTK interventions were ocular lubricants (90.9%), hypertonic solutions (77.9%), and bandage contact lenses (50.9%). 36 eyes had undergone surgical interventions such as stromal puncture, epithelial debridement, or diamond burr polishing. Post-PTK, 78% of patients did not require any subsequent therapies, 20% required ongoing drops and 6 patients (1.1%) reported no symptom improvement. All 6 eyes were successfully retreated with PTK between 11.3±14.9 months from initial PTK. All study patients showed no significant differences in best corrected visual acuity pre vs. postoperatively. When compared to other surgical options, PTK is potentially more costly but frequently more effective and has a high safety profile. The third-party public health vetted nature of this study, the high patient satisfaction, and the low recurrence rate of RCES suggest that PTK should be considered at an earlier stage in the management of RCES.

Phototherapeutic keratectomy for epithelial basement membrane dystrophy : Impact of excimer laser systems used on the changes of visual acuity, refraction and astigmatism

Excimer laser-assisted phototherapeutic keratectomy (PTK) has become established as the gold standard in treatment of epithelial basement membrane dystrophy (EBMD), commonly also known as map-dot-fingerprint dystrophy (MDF). At the Department of Ophthalmology, Saarland University Medical Center in Homburg/Saar, systems from Zeiss Meditec and Schwind have been used. The outcomes of both were compared in this study. The retrospective study included patients who underwent PTK with a diagnosis of MDF between 2007 and 2017. A total of 170 operations were performed using Zeiss Meditec MEL-70 (Carl Zeiss Meditec AG, Jena, Germany) and 98 using aSchwind eye-tech-solutions Amaris 750S laser (Schwind eye-tech-solutions GmbH, Kleinostheim, Germany). Preoperative and postoperative data for visual acuity, refraction and astigmatism as well as curvature data from the Pentacam and endothelial cell count were collected. The follow-up period averaged 8months. In both groups visual acuity postoperatively was significantly better (Zeiss: p < 0.001, Schwind p < 0.004). The improvement in the Schwind group was less than in the Zeiss group, which is the reason why there was asignificant difference between the laser systems postoperatively (p < 0.017). There were no significant changes regarding the spherical equivalent after PTK. Regarding astigmatism, there was asignificant decrease in the Zeiss group (p < 0.042), while it did not change significantly in patients treated with Schwind laser (p < 0.217). Overall, this led to asignificant postoperative difference between both laser systems (p < 0.014). The PTK can be recommended as an effective treatment method for patients with EBMD, regardless of the laser systems used. Patients benefit from long relief from recurrences with improved or constant visual acuity and stable refraction.

Comparison of Epithelial Thickness Mapping in Normal Corneas with Different Types of Astigmatism.

Corneal epithelial thickness mapping has a wide range of applications including screening for keratoconus, screening for anterior basement membrane dystrophy, and assessment of dry eye. It also plays an important role in corneal laser refractive surgery. These all require an understanding of the epithelial thickness profile in a normal cornea as a reference. This study aimed to compare corneal epithelial thickness along different meridians in normal eyes with different types of corneal astigmatism. In this cross-sectional study, corneal topography and epithelial thickness mapping by anterior segment optical coherence tomography was performed for 154 normal eyes. Corneal astigmatism was classified based on the orientation of the steepest corneal meridian (with-the-rule [WTR], against-the-rule [ATR], and oblique) and the amount (low, moderate, and high). On a 9-mm epithelial thickness map, the thickness along the horizontal (180°), vertical (90°), and diagonal (45 and 135°) meridians was calculated. With-the-rule, oblique, and ATR astigmatisms were observed in 40, 31, and 29% of the eyes, respectively. In all types of astigmatism, the mean epithelial thickness was greater along the 180° meridian and thinner along the 90° meridian. There was no statistically significant difference in mean thickness along different meridians for WTR (P = .24) and oblique (P = .46) astigmatism, whereas the difference along the 180 and 90° meridians (P = .003) for ATR astigmatism was statistically significant. Also, there was a statistically significant difference in thickness in different types of astigmatism separately for each meridian (P < .05) so that the highest and lowest thicknesses were seen for ATR and oblique astigmatisms, respectively. The epithelial thickness showed no statistical difference in various amounts of astigmatism along different meridians. Thicker epithelium along the horizontal meridian in ATR may point to the surface regularizing functions of the epithelium to create a regular and smooth surface, but thickness assessment along the different meridians in oblique and WTR showed no curvature-dependent changes.

Phototherapeutic keratectomy versus epithelial debridement combined with anterior stromal puncture or diamond burr for recurrent corneal erosions

ObjectiveTo compare outcomes of phototherapeutic keratectomy (PTK) versus epithelial debridement combined with anterior stromal puncture (ASP) or diamond burr for the treatment of recurrent corneal erosions (RCES) in a large tertiary centre. MethodsPatients with a diagnosis of RCES secondary to trauma or epithelial basement membrane dystrophy who underwent a surgical procedure between 2009 and 2019 were included in the study. The following data were collected: demographics, ocular history, prior medical treatment, ocular surgeries, intervention, complete epithelialization at postoperative week 1, recurrences, and complications. Recurrence was defined as either an objective finding of a corneal epithelial defect or symptoms suggestive of recurrent epithelial erosion on history. Recurrence rate and time to epithelialization were compared between groups. ResultsA total of 97 eyes (73 patients) were included in the study. Mean patient age was 51 ± 16.1 years, and mean follow-up was 474 days. RCES was secondary to epithelial basement membrane dystrophy in 80% (n = 78 of 97), trauma (15%, n = 15 of 97), or idiopathic (4%, n = 4 of 97). Epithelial debridement with ASP was performed in 34 eyes (35%), diamond burr in 33 eyes (33%), and PTK in 30 eyes (31%). Compared with epithelial debridement with ASP (recurrence 29.4%), the recurrence rate was significantly lower for both the diamond burr (9.1%, p = 0.031) and PTK groups (10%, p = 0.048). The diamond burr and PTK groups also had a significantly higher rate of complete epithelialization at 1 week (p < 0.05). ConclusionCompared with epithelial debridement with ASP, diamond burr and PTK have significantly lower rates of recurrence and time to epithelialization and may be considered first for surgical management of RCES.

Ocular surface optimization before cataract surgery.

The evolution of refractive cataract surgery has increased patient expectations for visual outcomes following cataract surgery. Precise biometry and keratometry are critical for accurate intraocular lens (IOL) selection and favorable surgical outcomes. In patients with the ocular surface disease and corneal pathologies, preoperative measurements can often be erroneous, leading to postoperative refractive surprises and dissatisfied patients. Conditions such as dry eye disease, epithelial basement membrane dystrophy, Salzmann's nodular dystrophy, and pterygia need to be addressed thoroughly before performing cataract surgery to optimize the ocular surface, obtain high-quality preoperative measurements, and ultimately determine the appropriate IOLs. In this review, the various ocular surface pathologies affecting cataract surgery outcomes and options for treatment are discussed and the importance of optimization of the ocular surface before cataract surgery is reviewed.

Optimizing the ocular surface prior to cataract surgery.

Ocular surface disease can significantly impact the outcomes of cataract surgery. Recent studies have examined the efficacy of several new dry eye disease (DED) therapies, the extent to which epithelial debridement affects keratometric measurements in epithelial basement membrane dystrophy (EBMD) and Salzmann nodular degeneration (SND), and the predictability of refractive error following combined pterygium and cataract removal. This review aims to incorporate these newer studies in updating and further emphasizing the need for careful management and optimization of common ocular surface conditions prior to cataract surgery. Common ocular surface conditions such as DED, EBMD, SND, and pterygium can cause significant irregular astigmatism and higher-order aberrations. Their resolution can substantially alter biometry measurements in preparation for cataract surgery, affecting the final visual outcome. Newer therapies for DED, such as topical lifitegrast and thermal pulsation treatment, can aid in this optimization process. If superficial keratectomy or excisions of lesions on the ocular surface are performed, sufficient healing time is needed to allow the ocular surface to reach stability prior to biometry measurements. Ocular surface optimization is key to successful cataract surgery planning and reaching desired outcomes.

Intraoperative Swept-Source OCT-Based Corneal Topography for Measurement and Analysis of Stromal Surface After Epithelial Removal.

To assess intraoperative stromal topography measurements using swept-source optical coherence tomography (OCT)-based topography/tomography after epithelial removal and to analyze the epithelial contribution to the corneal topography and optics. This was a prospective series of 22 eyes of 19 patients referred to receive phototherapeutic keratotomy (PTK) for treatment of recurrent corneal erosion and a control group of 22 virgin eyes. Swept-source OCT corneal topography/tomography was obtained immediately before and immediately after mechanical deepithelialization before PTK. Epithelial thickness maps were obtained before the surgery using spectral-domain OCT in the control group and as a reference in the group with anterior basement membrane dystrophy. Topographic and optical characteristics, including the curvature, astigmatism, asphericity, and higher order aberrations of the cornea before and after deepithelialization were compared, and their differences correlated with the measurements derived from the epithelial thickness maps. Stromal topography measurements after deepithelialization were easily obtained and showed excellent repeatability. Assessment of corneal edema induced by deepithelialization revealed that it did not significantly affect the measured parameters. The stromal surface was steeper by 1.28 diopters, had higher with-the-rule astigmatism by 0.41 diopters, was more prolate, and had more higher order aberrations compared to the intact epithelialized corneal surface. These differences correlated well with the parameters derived from epithelial thickness maps. Measurement of stromal topography using swept-source OCT immediately after mechanical deepithelialization may be a viable method in therapeutic refractive surgery, where stromal topography-guided ablation is needed. A significant epithelial contribution to anterior corneal topography and optics was confirmed. [J Refract Surg. 2021;37(7):484-492.].

In vivo confocal microscopic images of atypical amiodarone-induced keratopathy in patient with epithelial basement membrane dystrophy

A 73-year-old man presented with bilateral corneal opacities. Slit-lamp biomicroscopy showed vortex and oval-shaped opacities. In vivo confocal microscopy (IVCM) showed findings characteristic of amiodarone-induced keratopathy along with epithelial basement membrane dystrophy (EBMD). The IVCM findings indicated that the oval-shaped opacities can be present with amiodarone-induced keratopathy in patients with EBMD.

Histomorphological study of corneal dystrophies

Introduction: The term Corneal Dystrophy refers to a rare heterogeneous group of genetically determined, bilateral, symmetric, primary diseases, restricted to cornea and not associated with previous ocular inflammation. The dystrophies are classified based on the layer of cornea involved, into superficial, stromal and posterior dystrophies, each of which is genetically determined. Though the clinical features are often characteristic, definitive diagnosis is possible only after histological examination. The management protocols and visual prognosis vary with the underlying conditions. The incidence of the subtypes varies with the geographic locations. Objective: To study the prevalence of various subtypes of Corneal Dystrophies in corneal button specimens obtained after penetrating keratoplasty in a referral ophthalmic institute and to correlate with the patient’s age and sex. Materials and Methods: Corneal button specimens received in the ocular pathology laboratory over a period of five years were reviewed. Histopathological features of Corneal Dystrophies were studied and subcategorised. Cliniopathological analysis was made. Results: Out of 660 corneal biopsies reviewed, 42 cases were of corneal dystrophy. The patients were between 2 and 71 years of age, with 14 males and 28 females. Macular dystrophy was the most common with 20 cases, followed by Congenital Hereditary Endothelial Dystrophy (CHED) and Fuch’s endothelial dystrophy (FECD), with 7 cases each. Epithelial basement membrane dystrophy, Reis Buckler Dystrophy (RBCD), Granular dystrophy were the other types. Conclusion: Histopathological sub categorisation of various types of Corneal Dystrophies not only helps in understanding the prevalence, but also in predicting the genetic link and prognosis of the disease category. Keywords: Cornea, CHED, Dystrophy, Fuch, Macular.

Assessment of corneal epithelial thickness mapping in epithelial basement membrane dystrophy.

To investigate the corneal epithelial thickness topography with optical coherence tomography (OCT) and its relationship with vision quality in epithelial basement membrane dystrophy (EBMD). 45 eyes of EBMD patients, 26 eyes of dry eye (DED) patients and 22 eyes of normal subjects were enrolled. All participants were subjected to 9-mm corneal epithelial mapping with OCT and vision quality was assessed with the optical quality analysis system using the objective scatter index (OSI). Central, superior, inferior, minimum, maximum, and standard deviation of epithelium thickness (Irregularity), were analysed and correlations with the OSI were calculated. The mean (±SD) central, inferior and maximum epithelial thicknesses of the EBMD patients (respectively, 56.4 (±8.1) μm, 58.9 (±6.4) μm, and 67.1 (±8.3) μm) were thicker compared to DED patients (P<0.05) and normal subjects (P<0.05). We found greater irregularity of epithelial thickness in EBMD (5.1±2.5 μm) compared to DED patients (2.6±1.0 μm) (P = 4.4.10-6) and normal subjects (2.1±0.7 μm) (P = 7.6.10-7). The mean OSI was worse in EBMD patients than in DED patients (P = 0.01) and compared to normal subjects (P = 0.02). The OSI correlated with the epithelial thickness irregularity (Spearman coefficient = 0.54; P = 2.65.10-5). The OCT pachymetry map demonstrated that EBMD patients had thicker corneal epithelium in the central and inferior region. These changes were correlated with objective measurements of vision quality. This OCT characterisation of the EMBD provides a better understanding of the epithelial behaviour in this dystrophy and its role in vision quality.

Laser refractive surgery in corneal dystrophies.

Twenty-eight case reports and case series published between 2000 and 2019 concerning laser refractive surgery in patients with corneal dystrophies, resulting in 173 eyes from 94 patients, were included in this systematic review. Best results were achieved in posterior corneal polymorphous and Cogan dystrophy. Unfavorable results were found in Avellino dystrophy and Fuchs endothelial corneal dystrophy (FECD). Photorefractive keratectomy was not indicated in Meesmann and Avellino dystrophy. Laser in situ keratomileusis was indicated in posterior polymorphous corneal dystrophy but not in FECD, Avellino, or Cogan dystrophy. Small-incision lenticule extraction and other dystrophies such as lattice, fleck, Lisch, or François did not achieve enough scientific evidence to report any recommendation.