Color vision, contrast sensitivity and higher order aberrations after photorefractive keratectomy

Abstract

Purpose: To evaluate the effect of myopic photorefractive keratectomy (PRK) on color vision, contrast sensitivity and higher order aberrations (HOAs). Patients and Methods: This prospective study was performed on 46 eyes of 23 patients with 3 to 6 diopter of myopia/myopic astigmatism undergoing PRK. Color vision using Fransworth- Munsell 100 hue test (©2011 X-Rite Inc., Michigan, U.S) and contrast sensitivity using CSV-1000 (Vector Vision, Dayton, OH) were tested preoperatively and 2 and 6 months postoperatively. HOAs were assessed using Zernike analysis map of Pentacam (OCULUS Optikgerate GmbH, Germany) preoperatively and 6 months postoperatively. Results: No significant change was observed in color vision following PRK. Contrast sensitivity function was also preserved except for an increase in 12 cycles per degree (cpd) spatial frequency 6 months after surgery (P = 0.04). Total HOAs and primary spherical aberrations (total, anterior and posterior surface) increased significantly (P < 0.001), however, primary coma showed no statistically significant change 6 months after surgery compared to baseline values. Induced total HOAs significantly correlated with change in primary vertical coma and total, anterior, and posterior primary spherical aberration. No significant correlation was found between the changes in contrast sensitivity, color vision and HOAs with the amount of preoperative sphere and cylinder. Conclusion: PRK with an aspheric profile in moderate myopia/ myopic astigmatism does not affect color vision and contrast sensitivity at 3, 6 and 18 cpd spatial frequencies. It increases total HOAs and spherical aberration, but not coma. It remains a good option for refractive correction of moderate. Keywords: Color vision, Contrast Sensitivity, Higher order aberrations, Photorefractive keratectomy.