Measurement and Morphology of Corneal Endothelial Cell Density in Myopic Eyes of Adult Females Using a Non Contact Specular Microscope: A Cross-Sectional Study

Abstract

Introduction: A non contact specular microscope has been used to acquire the morphology of the corneal endothelial cell layer. This analysis provides measurements of the Coefficient of Variation (CV), the hexagonal appearance of the cells, and the mean corneal Endothelial Cell Density (ECD). These parameters are used to assess the function of the corneal endothelial layer. Aim: To evaluate the average corneal ECD, Hexagonality (HEX), CV, and their relationship with myopia in young females. Materials and Methods: The present cross-sectional study was conducted over a period of five months, from November 2016 to March 2017 at the clinics of the Department of Optometry and Vision Science, College of Applied Medical Science, King Saud University, Riyadh, Saudi Arabia and involved 107 eyes of healthy subjects aged 18-25 years. The participants’ refraction was estimated using an automatic refractor. Non contact specular microscopy was performed on emmetropic and myopic subjects. The average of three successive estimations of ECD, hexagonal appearance, and CV in cell size were recorded. Statistical analysis was performed using the Statistical Package for the Social Sciences (SPSS) program (version 22.0), and the independent student’s t-test was used to compare the means of various variables between low and moderate myopia. Results: The study included the right eyes of 107 healthy Saudi female subjects aged 18-25 years, who were divided into three groups based on their refractive errors. Non contact specular microscopy was performed on emmetropic (n=36, 20.58±1.20 years and mean Spherical Equivalent (SE) of -0.01±0.23 D), low myopic (n=49, 20.63±1.51 years and SE of -1.19±0.68 D), and moderate myopic (n=22, 20.64±1.26 years with mean SE of -4.15±0.90 D) subjects. The mean ECD in low myopic eyes was 2799.59±184.39 per square millimetre, the mean CV was 26.67±4.03 percent, and the mean hexagonal appearance of the cells was 67.69±4.82%. The average ECD, mean CV, and hexagonal appearance in moderate myopic eyes were found to be 2722.36±143/mm2 , 26.68±3.57%, and 68.73±5.87%, respectively. The results showed no statistically significant differences in ECD (p>0.05) and hexagonal appearance (p>0.05) in the cells of moderate and low myopic eyes. Conclusion: The present study found no significant relationship between corneal endothelial parameters and mild to moderate myopic eyes.