Factors influencing central corneal thickness in a Turkish population

The aim of this study is to find out the central corneal thickness (CCT) values for a Turkish patient group and to investigate the possible influences of age, sex, IOP, refractive status, keratometry readings, systemic disorders (hypertension, diabetes mellitus, hyperlipidemia, heart disease and asthma) on CCT values.

Six hundred twenty five subjects (276 male (44%), 349 female (56%)) of ages 6 to 88 years were recruited. Subjects who had corneal diseases, purulent conjunctivitis or blepharitis were excluded. Refraction and keratometry readings were made by MRK-3100 premium auto-ref/keratometer, IOP was measured by Reichert AT-555 auto noncontact pneumotonometer.

Mean age was 44.1 +/- 16.6 years +/- SD for male subjects, 41.0 +/- 16.9 for females. Mean CCT +/- SD values for male was 552.2 +/- 35.9 microm, for female was 552.3 +/- 35.4 microm, respectively. There was no significant difference between right and left eye CCT values for both genders. Age and CCT was not correlated for the whole study group but there was a slight negative correlation in male subjects. IOP and CCT had moderately significant correlation for males and females. There was a slight significant correlation between Kh-Kv and CCT values for the whole group. In a multivariate regression model only Kv values seemed to affect CCT values.

There are studies showing the variation of CCT values among different nations and ethnicities. There is no agreement about the relationship between age, IOP, Kh-Kv, spherical equivalence of refractive error, systemic disorders, menopause and CCT. In our study CCT was correlated with Kh-Kv and IOP in correlation analysis but in multivariate regression analysis only Kv appeared to influence corneal thickness.