Abstract:

Objective     To analyze visual performance in keratoconus with rigid gas permeable contact lens (RGPCL). Methods      18 keratoconic patients （36 eyes） who were fitted with RGPCL were enrolled as keratoconus group. 9 myopic patients(18 eyes) with RGPCL were enrolled as the myopia group. Visual acuity(VA) and contrast sensitivity were examined to evaluate visual performance(VP). Corneal astigmatism and wavefront error were measured to analyze the influencing factors of VP. Results    All keratoconic eyes got corrected VA of 0.6 or better.61.11% of them reached 1.0. There was no difference between the two groups in low frequency of contrast sensitivity（P>0.05）.But in the middle frequency of light-off contrast sensitivity and in the high frequency of contrast sensitivity,the keratoconus group was significantly lower than the myopia group(P<0.05). Corneal astigmatism was reduced from (8.25±3.61)D to (1.25±0.13)D in the keratoconus group and from(1.28±0.34)D to (0.42±0.06)D in the myopia group. The root-meansquare of total higher-order aberrations (HOAs), coma-like aberration and spherical-like aberrations in the keratoconus group were significantly higher than those in the myopia group(P<0.05). Conclusion     Through RGPCL, keratoconic eyes can get corrected VA as well as myopic eyes with RGPCL, but can not get ideal visual performance. The degradation of visual performance may be related to residual corneal astigmatism and HOAs in keratoconic eyes with RGPCL.

Key words: Keratoconus； Contact lens； Contrast sensitivity； Visual performance