Assessment of aberrations and visual quality differences between myopic and astigmatic eyes before and after contact lens application

Abstract

OBJECTIVE:To evaluate the aberration and visual quality differences between myopic and astigmatic eyes before and after contact lens application by using corneal aberrometer and low- contrast sensitivity chart.METHODS:Eighty eyes of 40 patients were included in this study. Patients were divided into two groups as myopic (40 eyes, n=20) and astigmatic groups (40 eyes, n=20). We used aspheric Balafilcon A (Purevision and Purevision Toric Bausch&Lomb, Rochester, USA) lenses for each group. Corneal aberrations and low-contrast sensitivity values were measured and compared for each patient in both groups.RESULTS:There were no statistically significant differences between myopic and astigmatic groups when we compared low-contrast sensitivity values for both on- and off-eyes. Mean total higher-order aberration (HOA) values for off-eye, were 0.29±0.10 μm, and 0.33±0.10 μm for on-eye in the myopic group, while they were 0.42±0.14 μm in off-eye and 0.37±0.23 μm in on-eye in the astigmatic group. Off-eye mean coma, irregular astigmatism and total higher-order aberration RMS (root-mean-square) values were significantly higher in the astigmatic group compared to the myopic group (p=0.006, p=0.001, p=0.001) but mean on-eye RMS values were not.CONCLUSION:Myopic and astigmatic patients differ in terms of high-order aberrations and these differences cannot be equalized after contact lens application, but visual quality can be improved in both patients by using contact lenses.

Evaluation of the Effects of Photochromic Contact Lens on Visual Quality and Pupillary Diameter: Cross-Sectional Study

“…In a study evaluating the effect of CL insertion on visual quality and aberrations, it was found that transparent CL did not change low contrast sensitivity. 13 We think that the multiple light reflections formed by the pre-lens tear film and the anterior and posterior surface of the CL are effective in reducing the contrast sensitivity at high frequencies in our study. In the literature, it has been stated that the reason for the decrease in contrast sensitivity with CL insertion is induced aberrations.…”

Does Long-term Soft Contact Lens Wear Affect Corneal and Anterior Chamber Parameters?

“…This result is in line with previous studies that have found improved visual quality and acuity with toric SCLs in low and moderate astigmatic eyes. 14 , 15 We believe that with a good SCL-cornea adaptation process, the mechanical properties of contact lenses and the toric designs result in fewer aberrations with toric lenses compared to glasses.…”