Purpose:

To investigate the relationship amongst refraction, central corneal thickness (CCT) and keratometric measurements.

Methods:

A retrospective study of the subjective refraction of 1022 eyes of 511 consecutive subjects who presented for refractive surgery evaluation was performed. Of the subjects, 241(48%) were male and 270(52%) were female. Mean age of male and female were 32.1±9 and 30.1±8.1 respectively. Javal Keratometer was used for keratometric measurements. CCT was obtained with DGH 4000B A-Scan/Pachymeter. The statistical forecasting methods used are Mann-Whitney U-test, Spearman Correlation, Wilcoxon signed rank test, Kruskal-Wallis methods as implemented in the software package SPSS version 11.5. A p-value of <0.05 was considered to be statistically significant.

Results:

The relation between the age of the patients and CCT, and keratometric measurements were not statistically significant (p=0.598, p=0.403) respectively. While CCT were higher in male p=0.002), keratometric values were higher in female (p=0.0001). Spherical equivalent (SE) showed a correlation with CCT values (p=0.04), and a negative lineer correlation with the keratometric values (p=0.0001). While females were found to be more myopic, males were more hyperopic (p=0.0001). CCT were higher in the eyes those >+5.00 Diopter(D) (p=0.04), and keratometric values were higher in the eyes those less than -6.00 D (p=0.0001).

Conclusions:

Males had lower keratometric measurements and were more likely to be hyperopic or mix hyperopic astigmatism than female. Females were more mix myopic astigmatism than males. CCT was higher in high hyperops and low in high myopes. A negative linear correlation between the keratometric measurements and SE was found. We believe that, investigation of these parameters would be helpful in better understanding of the biometric characteristics of the eye and choosing the appropriate technique in refractive surgery.

Keywords: Central corneal thickness, keratometry, pachymetry, refractive error