Central corneal thickness and its relationship to ocular parameters in young adult myopic eyes

Background: An investigation was carried out to find the distribution of central corneal thickness (CCT) and the association between CCT and ocular factors in a cohort of myopic Chinese adults who underwent laser refractive surgery. Methods: Medical records of 1,190 subjects (754 males) aged from 18 to 44 years (21.5 +/- 3.5 years for males and 24.9 +/- 5.5 years for females) undergoing myopic refractive surgery were filtered and analysed. Each parameter was stratified by gender and eye, respectively. Multi-linear and linear regressions were used to analyse the effect of intraocular pressure (IOP), period of contact lens wearing, gender, age, refractive error, mean corneal curvature (K) and ocular high-order aberration at 5.0-mm zone on CCT. Results: The mean CCT was 539.2 +/- 37.8 mu m in the whole study population. Males had greater CCT than females (p < 0.001), while females had greater K than males (p < 0.001). There was no difference in IOP, ocular cylinder or higher-order aberrations between genders. No interocular difference was identified either in IOP or K. Multi-linear regression model revealed that only gender, IOP and K were correlated with CCT (standardised coefficients of right eye are -0.101, p = 0.001 for gender, 0.231, p < 0.001 for IOP and -0.080, p = 0.009 for K; standardised coefficients of left eye are -0.090, p = 0.002 for gender, 0.310, p < 0.001 for IOP and -0.076, p = 0.015 for K). Conclusions: In a population of myopic candidates for laser refractive surgery, only gender, IOP and K were correlated with CCT.