The Effects of Gender, Age, and Refractive Error on Corneal and Conjunctival Epithelial and Overall Thicknesses

Objective: To evaluate the corneal, conjunctival epithelial and overall thicknesses measured by anterior segment optical coherence tomography (OCT) in healthy population. Methods: This retrospective study included 134 eyes of 134 healthy individuals who were undergone a Cirrus HD-OCT examination using the Anterior Segment 5 Line Raster protocol. Corneal, conjunctival epithelial and overall thicknesses were measured on OCT images. The average values of four OCT parameters were compared between sexes and among the six subgroups with respect to age. Results: The average corneal epithelial and overall thicknesses were 51.30±4.60 μm and 532.47±37.30 μm, respectively. The average conjunctival epithelial and overall thicknesses were 47.20±8.03 μm and 237.07±40.62 μm, respectively. All of the measurements were thicker in males compared to females, however the significant difference was found for only corneal epithelium (p=0.043). Using the Spearman correlation coefficient, central corneal and conjunctival epithelial thicknesses showed significant negative correlations with age (p=0.006, p=0.005, respectively) and refraction (p=0.040, p=0.033, respectively). Conclusion: Ocular surface parameters measured by anterior segment OCT were gender, age, and refraction-related. Thus, further studies conducted to evaluate the corneal and conjunctival thicknesses should involve gender, age, and refraction-matched control groups. J Clin Exp Invest 2016; 7 (1): 78-82 Key words: Anterior segment optical coherence tomography, epithelial thickness, spherical equivalent