Table 1. The demographic and clinical characteristics of patients.

Variables	Values
Age, year
Mean±SD	62±13
Range	28–72
Gender
F/M	24/15
Central corneal thickness, μm
Mean±SD	542±40
Range	471–603
Spherical equivalent, D
Mean±SD	0.87±1.49
Range	−2.75 to +3.50

Abbreviation: D, diopter.