The Distribution of Corneal Thickness in Rural Population

Abstract

To determine the distribution of corneal thickness and its associated factors in the over 5-year-old population in the north and south rural areas in Iran. In this study, samples were selected using multi-stage cluster sampling. After vision and refraction tests and the slit lamp exam, the central corneal thickness (CCT), apical corneal thickness (ACT), and the thickness at four peripheral areas of the cornea were measured using Pentacam. Of the 3851 selected samples, after applying the exclusion criteria, the analysis was done on data from 2681 people. The mean age of the participants was 36.03±18.51 years, ranging from 6 to 90 years, and 58.1% of them were female. Mean CCT and ACT were 533.87 μm (95%CI: 532.05 -535.69) and 536.72 μm (95%CI: 534.9 -538.54), respectively. Mean peripheral corneal thickness was 637.46 μm (95%CI: 635.09 -639.83) in the superior quadrant, and 594.34 μm (95%CI: 592.2 -596.47), 620.81 μm (95%CI: 618.66 -622.97), and 584.55 μm (95%CI: 582.18 -586.93) in the inferior, nasal, and temporal quadrants, respectively. Linear regression analysis showed significant associations between CCT and gender (P=0.001), age (P<0.001), geographical location of residence (P<0.001), the radius of corneal curvature (P<0.001), anterior chamber depth (P<0.001), and corneal volume (P<0.001). This study is one of the few studies describing the distribution of the corneal thickness in a population of over 5-year-olds using Pentacam. Gender, anterior chamber depth, and corneal radius of curvature are some of the factors associated with CCT.

Keywords

• Corneal thickness
• Cross-sectional study
• Distribution