Prevalence of inherited retinal diseases in a large Egyptian cohort.

BACKGROUND: Inherited retinal diseases form a rare, highly heterogeneous group of genetic disorders characterized by retinal degeneration. It is considered one of the leading causes of debilitating visual loss and blindness in children and young adults. Despite this few population-based data studies on prevalence of inherited retinal diseases exist. Moreover, prevalence can vary widely depending on geographical area, population ethnicity and cultural habits. PURPOSE: To report the prevalence of different subtypes of Inherited retinal diseases in a large Egyptian cohort in a retrospective, hospital-based, cross-sectional study. METHODS: We conducted an extensive electronic medical record search for all the patients attending the outpatient clinic and investigation unit of Ain Shams University Hospital and the two branches of Watany Eye Hospital in the period between January 2015 and October 2022 aiming to identify the prevalence rate of different types of IRDs, patient demographics and stratify them according to their phenotype. RESULTS: We examined the electronic medical records of 478 222 patients, 971 patients were diagnosed with IRD by clinical examination with or without any of the following investigations: color fundus photography, fundus autofluorescence, fundus fluorescein angiography, optical coherence tomography and/or electrophysiological studies as electroretinogram, visual evoked potential and electrooculogram. The overall prevalence was 0.2%. The most common IRD encountered was isolated retinitis pigmentosa with a percentage of 78.9% followed by Stargardt disease at 6.3%, cone-rod dystrophy at 2.0%, autosomal recessive bestrophinopathy at 1.9% and unspecified IRD at 1.5%. CONCLUSION: Retinitis pigmentosa was the most common IRD encountered followed by Stargardt disease. Many of the dystrophies are the subject of clinical intervention trials, and population-based epidemiological data can guide phenotype-based genetic testing and help assess the future need for treatment.

Diagnostic accuracy of different keratoconus detection indices of pentacam in paediatric eyes.

OBJECTIVE: No diagnostic gold standard for keratoconus in children and adolescents exists. Our objective was investigating the diagnostic accuracy of various indices for keratoconus (KC) detection in paediatric eyes. METHODS: All retrievable data of significance from 432 normal right paediatric eyes and 48 eyes of paediatric KC and forme fruste KC (FFKC), imaged by use of a rotating Scheimpflug camera (Oculyzer II, Pentacam HR) between December 2013 and October 2018 at Watany Eye Hospitals, Cairo, Egypt, including Scheimpflug images data, were collected. The area under the receiver operating characteristic curve (AUROC) was calculated for different indices in this retrospective descriptive study. RESULTS: All 36 tested indices showed discriminative power differentiating KC and FFKC from normal corneas (AUROC P-value <0.05), except AC volume, AC angle, and horizontal decentrations of the steepest and thinnest points. The 32 indices showed variable degrees of diagnostic accuracy. The highest AUROC was that of the corneal assessment index from the relational thickness and other OCULUS values (CAIRO 8). Only 8 indices showed non-inferiority to it, namely, Ambrosio's relational thickness maximum (ART max) and avg, the pachymetric progression index maximum (PPI max) and avg, the back elevation from the best-fit toric ellipsoid (BE BFTE), the KC index (KI), the topographic KC indices (TKC), and the index of height decentration (IHD) (P > 0.05). CONCLUSIONS: The 8 most useful rotating Scheimpflug imaging indices for KC detection in paediatric eyes are CAIRO 8 followed by ART max and avg, PPI max and avg, BE BFTE, KI, TKC, and IHD.

Exfoliation Syndrome in Egypt: Prevalence and Association with Cataract in a Large Cohort.

INTRODUCTION: Exfoliation syndrome is an age-related disease leading to ocular and systemic complications. We aimed to evaluate the prevalence of exfoliation syndrome (XFS) in Egypt and its association with cataract as one of its comorbidities. METHODS: In a retrospective, hospital-based study, 155,032 Egyptians aged over 40 years from all 27 Egyptian governorates were evaluated for the prevalence of XFS and cataract in the period between January 2015 and June 2020. RESULTS: A total of 2448 (1.6%) of the studied subjects had XFS. Their mean age was 71.2 ± 9.62 years which was significantly higher than those of subjects with no XFS. Men comprised 1348 (55.1%) of those diagnosed with XFS and this association was statistically significant (OR 1.57, 95% CI 1.45-1.70). Considering the ratio between subjects in our cohort from each region and its real population, the overall corrected prevalence in Egypt was 4.49% (Territorial regions 6.89%, Upper Egypt 5.51%, Lower Egypt 4.38%, and Greater Cairo 3.29%). Among all subjects with XFS, cataract was found in 2150 subjects (87.8%) and XFS represented 6.4% of all subjects diagnosed with cataract in our cohort (n = 33,610). Among subjects with no cataract (n = 121,422), 298 subjects had XFS (OR 0.04, 95% CI 0.03-0.04). CONCLUSION: Egypt has a moderate XFS prevalence compared to other countries. There is a strong association between XFS and cataract, and XFS was more common in elderly males. The results can be explained by differences in diet, ethnicity, climate, and maybe other factors.

Exfoliation syndrome (XFS) is an age-related disease characterized by the deposition of distinctive material in many eye and systemic tissues, with resultant eye (lens opacities, chronic rise in eye pressure, and more frequent surgical complications during lens surgeries) and systemic health implications (hearing loss and cardiovascular diseases). It is a universal disease that occurs in virtually all countries and whose percentage among individuals varies from one country to another, hence the importance of studies determining its percentage. We conducted our study on a large group of individuals encompassing more than 155,000 individuals aged over 40 years in the period between January 2015 and June 2020, to determine how frequent it is in Egypt and its different regions, and determine its common associations. Overall, it had moderate frequency, most commonly found among older subjects, men, those residing in territorial areas of Egypt as well as those having cataracts and lens opacities. Given Egypt's unique geographical location being a transcontinental country (Afro-Asian), and belonging to Middle Eastern as well as Mediterranean countries, our results can be extrapolated to other neighboring countries and are not exclusive to Egypt. Studying this prevalence will give insights into risk factors for the disease that could possibly be modified, as well as determining the population at risk to help stakeholders to design effective screening programs.

Correlation between ocular biometric parameters and corneal endothelium in a sample of young Egyptian adults.

Background: To evaluate the normative values of corneal endothelial cell parameters within a group of healthy young Egyptian adults using specular microscopy and to examine any correlations between endothelial parameters and refractive or biometric parameters. Methods: In this cross-sectional study, specular microscopy was used to study the right eyes of 150 healthy young volunteers and evaluated endothelial cell parameters, including cellular density, hexagonality (HEX), and coefficient of variation (CV) at 15 different points on the back corneal surface, which were later grouped into the central zone and either four quadrants or three annular zones. The same eyes underwent refractive and biometric assessments. Results: Hundred fifty healthy adults were examined, and the age ranged from 20 to 30 years, with a median of 23 (interquartile range, 21‒27) years. The mean (standard deviation) of central cell density was 2902.7 (270.7) cells/mm2. The superior paracentral area had the lowest mean density (2895.8 cells/mm2), but the highest mean HEX (67.7%), while the inferior peripheral area had the highest mean density (3100.5 cells/ mm2) but the lowest mean HEX (64%). The difference in cell density among the three annular zones was not statistically significant (P = 0.365). However, HEX and CV in the central and paracentral zones differed statistically significantly from those of the peripheral zone (P < 0.001 and P = 0.014, respectively). Weak but non-significant correlations were detected between endothelial cell density and all measured refractive and biometric parameters. Conclusions: The findings of this study provided useful normative biometric and specular data in a specific age group and a specific population, and could be useful in planning intraocular surgery in young Egyptian adults. However, future longitudinal studies with a larger sample could refine more endothelial cell parameter specifications over time.

Normative Values of Various Pentacam HR Parameters for Pediatric Corneas.

PURPOSE: To provide a normative database of several Pentacam parameters for a healthy pediatric population. METHODS: This was a retrospective study conducted at Al Watany Eye Hospitals, Cairo, Egypt. We explored the Pentacam HR database and collected the data of 432 normal right eyes of children and teenagers aged 3 to 18 years. The subjects were classified into the following 3 groups: group 1 (3-6 years, 17 eyes), group 2 (6-12 years, 126 eyes), and group 3 (12-18 years, 289 eyes). The parameters of the study cohort were compared with those of a healthy adult cohort. RESULTS: The mean age of the study cohort was 13.5 (13.2-13.8) years. There were significant differences in the following indices among the 3 age groups: anterior chamber (depth and volume), curvature (index of height decentration, index of vertical asymmetry, and center keratoconus index), elevation (front and back elevations from the best fit toric ellipsoid), and pachymetric (minimum and average pachymetric progression indices and average Ambrosio relational thickness) parameters (P values 0.001, 0.001, 0.002, 0.04, <0.001, <0.001, 0.03, 0.02, 0.01, and 0.03, respectively). CONCLUSIONS: There were significant differences in the normative values of several Pentacam indices between the pediatric and adult cohorts. Based on this finding, it is more credible to incorporate separate software cutoff values for pediatric patients. However, because there were no clinically significant differences in the parameters of the pediatric subgroups, there is no need to consider a separate cutoff value for each pediatric age range.

Pentacam HR Indices Variation in Normal Corneas with Different Corneal Thickness.

PURPOSE: To evaluate the effect of variable corneal thickness on Pentacam HR diagnostic indices in normal corneas. METHODS: Retrospective study was conducted at Al Watany Eye Hospital, Cairo, Egypt. Consecutive 160 eyes of young myopic subjects without KC were evaluated using Pentacam HR (WaveLight Allegro Oculyzer II, Erlangen, Germany). The elevation- and thickness-based indices were recorded. Enrolled corneas were categorized into three groups according to TCT quartiles; group 1 (39 eyes) included corneas with TCT <523 µm, group 2 (81 eyes) with TCT between 523 and 564 µm, while group 3 (40 eyes) enrolled TCT >564 µm. The possible effect of pachymetry on Pentacam HR indices was assessed using partial correlation tests. RESULTS: In normal corneas, back elevation from best fit sphere (BE from BFS) and that from best fit toric ellipsoid (BFTE) were the elevation indices that showed statistically significant differences among groups (P=0.013 and 0.019, respectively). Regarding pachymetric indices, maximum pachymetry progression index (PPI max) showed statistical significance (P=0.001). Partial correlations, after excluding age and refractive error effects, showed that TCT was correlated with BE from BFS, BE from BFTE, and PPI max (P=0.001, 0.001,0.002, respectively). CONCLUSIONS: Some Pentacam HR indices varied with different corneal thickness in normal corneas. This necessitates inclusion of pachymetric subgroups in the normative database. The use of the more robust indices (average pachymetry progression index and front elevations) is recommended in relatively thin or thick corneas.

Effect of Age on Pentacam Keratoconus Indices.

PURPOSE: To assess the effect of age on elevation and pachymetric Pentacam keratoconus (KC) detection indices, and the need to adjust normative values accordingly. METHODS: In a retrospective study, 95 eyes of myopic normal subjects without KC were evaluated using the OCULUS Pentacam, with an age range of 17.4 to 46.8 years. Subjects were categorised into three groups according to their age: the first included those younger than 21 years (19 eyes), the second was for the age range of 21-40 years (65 eyes), and the third comprised subjects older than 40 years (11 eyes). RESULTS: There were statistically significant differences among the three groups regarding many elevation indices: AE from BFS, PE from BFS, and PE minus AE from BFS (P = 0.003, 0.010, and <0.001, resp.), and pachymetric indices: PPI avg, PPI max, ART avg, ART max, and diagonal decentration of the thinnest point (P = <0.001, 0.024, 0.003, 0.026, and 0.026, resp.). On comparing subjects below 21 years to those above 40 years, there was a statistically significant decrease of both PE from BFS and PE minus AE (P = 0.005 and <0.001, resp.) and statistically significant increase in AE from BFS (P = 0.001). CONCLUSIONS: Age is an important determinant of elevation indices, significantly altering their normative values. The use of the more robust pachymetry, rather than elevation, indices is recommended in subjects below 21 or above 40 years of age.

Clinical trial comparing autogenous fascia lata sling and Gore-Tex suspension in bilateral congenital ptosis.

PURPOSE: To study the effect of autogenous fascia lata sling (AFLS) versus Gore-Tex suspension (GTS) regarding the functional and aesthetic outcomes in patients with bilateral congenital ptosis. PATIENTS AND METHODS: A prospective comparative randomized single-center study enrolled 110 patients with bilateral congenital ptosis. One group (n=55) underwent AFLS and the second group (n=55) underwent GTS. Exclusion criteria were good levator function, absent Bell's phenomenon, and abnormal ocular motility. Follow-up period was 2 years. Functional outcome was measured from digital photos by analysis of upper eyelid margin position relative to the superior limbus and classified as very good (<3 mm), good (3-5 mm), poor (>5 mm), and recurrent. Aesthetic outcome was assessed in terms of lid contour, symmetry of eyelid height, and lid crease presence. Complications were also reported. RESULTS: Failure rate (recurrence and complications) was less in AFLS (P=0.035). Symmetrical lid height and good contour were more frequently attained by AFLS (P=0.007 and 0.047, respectively). However, the frequency of very good, good, poor, recurrence, lagopthalmos, ectropion, infection, and formed lid crease individually showed no statistically significant difference (P=0.252, 0.482, 1, 0.489, 0.438, 1, 0.618, and 0.506, respectively). CONCLUSION: AFLS is a better choice in surgery for patients with bilateral congenital ptosis because it has fewer complications and a lesser recurrence rate than GTS.

Comparative analysis of corneal morphological changes after transversal and torsional phacoemulsification through 2.2 mm corneal incision.

PURPOSE: This paper compares and evaluates the corneal morphological changes occurring after cataract surgery through a 2.2 mm corneal incision. We use two platforms for comparison and evaluation, transversal and torsional phacoemulsification. PATIENTS AND METHODS: This study includes 139 consecutive cataractous eyes (nuclear color 2-4, according to the Lens Opacities Classification System III [LOCSIII]) of 82 patients undergoing cataract surgery through a 2.2 mm corneal incision. Two different phacoemulsification platforms were used and assigned randomly: we used the WhiteStar Signature(®) system with the Ellips™ FX transversal continuous ultrasound (US) mode for group I (mean age: 65.33 ± 6.97 years), and we used the Infiniti(®) system with the OZil(®) Intelligent Phaco (IP) torsional US mode for group II (mean age: 64.02 ± 7.55 years). The corneal endothelium and pachymetry were evaluated preoperatively and at 1 month postoperatively. Incision size changes were also evaluated. RESULTS: All surgeries were uneventful. Before intraocular lens implantation, the mean incision size was 2.24 ± 0.06 mm in both groups (P = 0.75). In terms of corneal endothelial cell density, neither preoperative (I vs II: 2304.1 ± 122.5 cell/mm(2) vs 2315.6 ± 83.1 cell/mm(2), P = 0.80) nor postoperative (I vs II: 2264.1 ± 124.3 cell/mm(2) vs 2270.3 ± 89.9 cell/mm(2), P = 0.98) differences between the groups were statistically significant. The mean endothelial cell density loss was 1.7% ± 1.6% and 2.0% ± 1.4% in groups I and II, respectively. Furthermore, no significant differences between groups I and II were found preoperatively (P = 0.40) and postoperatively (P = 0.68) in central pachymetry. With surgery, the mean increase in central pachymetry was 28.1 ± 23.6 µm and 24.0 ± 24.0 µm in groups I and II, respectively (P = 0.1). CONCLUSION: Ellips™ FX transversal and OZil(®) IP torsional phacoemulsification modes are safe for performing cataract surgery, inducing minimal corneal thickness and endothelial changes.