Corneal Thickness and Relating Factors in a Population-Based Study in Japan: The Tajimi Study

Purpose To evaluate central corneal thickness (CCT) in a Japanese population and to describe the relationship between CCT and other factors. Design Population-based cross-sectional study. Methods Reliable CCT measurements were obtained using specular-type pachymetry from 2,868 persons 40 years or older selected randomly from the population of Tajimi City. Results The CCT averaged 0.521 ± 0.032 mm (mean ± standard deviation). The CCT was thicker in men than in women ( P < .001) and was correlated with age (right eyes only), height, weight, diastolic blood pressure, systolic blood pressure (left eyes only), intraocular pressure (IOP), and corneal curvature ( P < .05, the Pearson correlation analyses). Multiple regression analysis showed that only gender, IOP, and corneal curvature were significantly ( P < .011) associated with CCT. Conclusions The mean CCT obtained using an optical method in a Japanese population was 0.521 mm. The CCT was associated significantly with gender, IOP, and corneal curvature but not with age in multiple regression analyses.