Correlation Of Central Corneal Thickness Across Varying Degrees Of Myopia: A Cross-Sectional Observational Study

Abstract

Background

Myopia, often referred to as nearsightedness, is a common refractive error that affects the eye's ability to focus light precisely on the retina. This condition results in clear vision for objects that are close but blurred vision for those at a distance. The purpose of this study is to analyze the correlation between central corneal thickness (CCT) and varying degrees of myopia in an adult Indian population.

Methods

A hospital-based cross-sectional observational study was conducted on 236 adults with myopia. Subjects were classified into mild (-0.25D to -3.00D), moderate (-3.00D to -6.00D), and high (> -6.00D) myopia. Central corneal thickness was measured using Anterior Segment Optical Coherence Tomography (AS-OCT). Data were statistically analyzed to evaluate CCT distributions and their relationship with the severity of myopia.

Results

There was a clear, significant decline in CCT with increasing grades of myopia. Mean CCT values were: Mild: 540μm, Moderate: 535μm, High: 525μm. Regression analysis showed that CCT decreased by approximately 2.0μm for every one-diopter increase in myopic error (β = –2.0, p = 0.013). Age was also negatively correlated with CCT (r = –0.15, p = 0.02), while gender had no significant effect.

Conclusion

CCT reduces progressively with higher degrees of myopia. This thinning has important implications for refractive surgery eligibility and risk stratification in myopic populations and Intraocular Pressure (IOP) monitoring in glaucoma suspects.