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K. Negishi, T. Kumanomido, M. Saiki, Y. Utsumi, K. Tsubota; Effect of Higher-Order Aberrations on Visual Function in Keratoconic Eyes With a Rigid Gas Permeable Contact Lens. Invest. Ophthalmol. Vis. Sci. 2007;48(13):2779.
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© ARVO (1962-2015); The Authors (2016-present)
To study the effect of higher-order aberrations (HOAs) on visual function in keratoconus with a rigid gas permeable (RGP) contact lens retrospectively.
Thirteen eyes of 10 subjects with keratoconus who wore a RGP contact lens (KC-RGP group), 15 eyes of nine normal subjects (normal group), and 14 eyes of nine subjects who wore a RGP contact lens (RGP group) who had no ocular diseases except for refractive errors and had 20/20 or better corrected visual acuity (VA) are included in this study. Visual acuity and contrast sensitivity function with CSV-1000 E charts were measured under photopic conditions in the three groups. The ocular HOAs in a 4-mm area were measured with the OPD-Scan wavefront aberrometer. The root-mean-square (RMS) of the third-, fourth-, fifth-, and sixth-order Zernike coefficients (total higher-order aberrations), the RMS of the third-order Zernike coefficients (S3) (coma-like aberration), the RMS of the fourth-order coefficients (S4) (spherical-like aberrations), and the area under the log contrast sensitivity function, one of the index of visual function, were evaluated in the three groups.The Kruskal-Wallis test and Scheffe’s F test were used to evaluate differences among the groups. Spearman’s correlation coefficient by rank was used to evaluate the correlation between total HOAs, S3, S4, and the area under the log contrast sensitivity function. A P value less than 0.05 was considered significant.
The area under the log contrast sensitivity function in the KC-RGP group (1.158±0.145) was significantly lower than in the other two groups (1.462±0.102 and 1.411±0.122, in normal and RGP group, respectively). The total HOA(µm) was 0.152±0.037, 0.188±0.081, and 0.538±0.327, S3(µ m) was 0.123±0.044, 0.160±0.079, and 0.496±0.297, S4(µm) was 0.067±0.027, 0.069±0.034, and 0.166±0.134 in normal, RGP, and KC-RGP group, respectively. The mean total higher-order aberrations, S3, and S4 in the KC-RGP group were significantly higher than in the other two groups. There were significant negative correlations between the area under the log contrast sensitivity function and the total higher-order aberrations, S3, and S4.
The visual performance in a keratoconic eye with a RGP contact lens degrades compared with normal eyes with and without RGP contact lenses, even if the corrected VA is good. The degradation is assumed to be related to residual HOAs in a keratoconic eye with a RGP contact lense.
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