Contrast sensitivity function after correcting residual wavefront aberrations during RGP lens wear.
OBJECTIVE
To investigate the effect on the contrast sensitivity function (CSF) of correcting the residual wavefront aberrations in myopic and keratoconic subjects wearing rigid gas permeable (RGP) contact lenses.


METHODS
Seventeen eyes of 16 myopic subjects and 20 eyes of 19 keratoconic subjects were included in this study. All eyes were habitually corrected with RGP lenses. The residual aberrations of the RGP lens-wearing eyes were compensated by an adaptive optics (AO) system. The contrast sensitivities were measured through a 4-mm artificial pupil at spatial frequencies of 2, 4, 8, 16, and 32 cycles per degree (cpd) during RGP lens wear for the myopic and keratoconic groups, respectively. The CSF measurements were repeated with and without AO correction. Comparisons of contrast sensitivity at all spatial frequencies with and without AO correction were performed respectively for the myopic and keratoconic groups during RGP lens wear.


RESULTS
In the myopic RGP lens-wearing group, the differences in contrast sensitivity at each spatial frequency, with and without AO correction, were not significant (all p values > 0.05). In the keratoconic RGP lens-wearing group, the contrast sensitivities at all spatial frequencies with AO correction were higher than those without AO correction, but differences only at the low (2 cpd) and intermediate (4, 8, and 16 cpd) spatial frequencies were significant (p = 0.039, 0.005, 0.001, and 0.007).


CONCLUSIONS
The residual aberrations significantly reduced the contrast sensitivities at low and intermediate spatial frequencies for keratoconic RGP lens-wearing eyes but did not have any effect on the CSF for the myopic RGP lens-wearing eyes. Developing techniques that could more completely correct the wavefront aberrations may improve visual performance in keratoconus.
*MS †PhD ‡MD Department of Optometry, West China School of Medicine, Sichuan University, Chengdu, Sichuan, China (BY, LL, ML, QL); Institute of Optics and Electronics, Chinese Academy of Sciences, Chengdu, Sichuan, China (BL, YD, HZ, Y Zhang); and Vision Research Lab, School of Life Sciences, University of Science and Technology of China, Hefei, China (Y Zhou).
Bi
B
Yang
Bo
B
Liang
Longqian
L
Liu
Meng
M
Liao
Qian
Q
Li
Yun
Y
Dai
Haoxin
H
Zhao
Yudong
Y
Zhang
Yifeng
Y
Zhou
D003261:Contact Lenses; D015350:Contrast Sensitivity / Q000502:physiology*; D057108:Corneal Wavefront Aberration / Q000503:physiopathology / Q000628:therapy*; D005260:Female; D006801:Humans; D007640:Keratoconus / Q000503:physiopathology / Q000628:therapy*; D008297:Male; D009216:Myopia / Q000503:physiopathology / Q000628:therapy*; D012029:Refraction, Ocular / Q000502:physiology; D055815:Young Adult