Factors affecting the central corneal thickness of Hong Kong-Chinese

Purpose. The aims of this study were to investigate the effect of age, intraocular pressure, refractive error (spherical equivalent) and corneal curvatures on the central corneal thickness of Hong Kong-Chinese. We also compared the central corneal thickness of Hong Kong-Chinese with those previously reported for other national/ethnic groups. Methods. The central corneal thicknesses of 151 subjects of age 10-60 yrs were measured using an ultrasound pachometer. Intraocular pressure, refractive error and the corneal curvatures of these subjects were also recorded. Results. The mean ± SD central corneal thickness of the right eye and left eye were 575 ± 32 μm and 574 ± 31 μm respectively. No significant difference in central corneal thickness was found between the right and left eyes or between male and female subjects. Central corneal thickness decreased with increasing age but the effect appeared to be due to differences in female subjects only. The maximum decrease in central corneal thickness occurred in subjects in the age group of 10-25 yrs, and in this age group, central corneal thickness and age was significantly correlated in both male and female subjects. Intraocular pressure and central corneal thickness was significantly correlated. There was no correlation between central corneal thickness and refractive error or between central corneal thickness and corneal curvatures. Conclusions. Central corneal thickness decreased with increasing age but this appeared to be due to female subjects only. Central corneal thickness was significantly correlated with intraocular pressure, but not with refractive error or corneal curvatures. Our subjects also had significantly thicker corneas than those reported for Caucasian subjects.