Purpose: To evaluate the relationship between the thinnest point of the cornea and the refractive state, keratometry readings, age, sex and ocular side.
Methods: Medical records of 1035 subjects who underwent preoperative examination at our laser refractive center ( Sohag city, Egypt) were retroscpectively reviewed from January 2010 to December 2010. Patients' age, sex, central corneal thickness (CCT), refractive status and keratometry readings were obtained. Correlational analysis was performed using Pearson's correlation coeffieicnts. The influence of ocular parameters on the least corneal thickness was assessed by analysis of variance (ANOVA)and multivariate analysis.
Results: The mean corneal thickness of the thinnest point of the cornea was 539.37±35.75µm. There were no significant differences in the mean least corneal thickness between myopic and hyperopic eyes (P=0.40), left and right (P=0.41) or age groups (P=0.59). However, the minimum corneal thickness decreases with increasing keratometry values (P<0.0001). Indeed keratometry values affected the least corneal thickness as assessed both by ANOVA(r=-0.15; P<0.001) and multivariate analysis (P<0.0001).
Conclusion: Keratometry readings ahould be obtained at preoperative assessment for refractive surgery.moreover, caution should be observed when operating on patients with high keratometry readings.