Corneal thickness measured by Pentacam in myopic eyes and its related factors analysis

Objective To compare the difference of the thinnest central corneal thickness in myopic eyes using Pentacam and A-scan ultrasound pachymetry,and assess the related effective factors.Methods The thinnest central corneal thickness in 300 eyes of 150 myopic patients before laser refractive surgeries was measured by Pentacam and A-scan ultrasonic pachymetry.The differences in the measurements obtained by two methods were statistically analyzed.Results The thinnest central corneal thickness measured by Pentacam and A-scan ultrasonic pachymetry were(543.7±26.3)μm and(539.2±27.4)μm,respectively,the correlation between them was high(r=0.97,P=0.000 1).The thickness measured by Pentacam was thicker than that by A-scan ultrasonic pachymetry,the difference was(4.4±7.0)μm,there was significant difference(P=0.000 1).The difference was correlated with the corneal thickness measured by A-scan ultrasonic pachymetry and the age(P=0.000 1),while there was no correlation with refractive power,gender,corneal diameter and corneal curvature.Conclusion The corneal thickness measured by Pentacam is thicker than that by A-scan ultrasound pachymetry in myopic eyes.Although they have well cooperativity,they cannot be simply used interchangeably.