Study of Post Operative Regression after Photorefractive Keratectomy for Treatment of Hyperopia and Hyperopic Astigmatism

Purpose: To study post operative regression rates after photorefractive keratectomy among patients with hyperopia and hyperopic astigmatism with follow-up of at least six months. Patients and Methods:  In this historical cohort study, 171 eyes from 91 patients with moderate hyperopia and hyperopic astigmatism were treated using Bausch and Lomb Technolas 217 Z Excimer Laser. Pre-operation evaluation included; best spectacle corrected visual acuity, manifest and cycloplegic refraction, diameter of optical zone, central corneal thickness and simulated keratometry. Postoperative evaluation, performed at least six months after the procedure, included measurement of corneal curvature, manifest and cycloplegic refraction, best corrected visual acuity, uncorrected visual acuity, refraction manifest, haze, and any pathologic finding. Results: The mean regression was 0.35 ± 1.04. Post surgical manifest refraction equivalent in ± 0.5 diopter range of surgeon’s desired refraction was observed in 57.1 % of eyes. Manifest refraction equivalent in ± 1.00 diopter range was observed in 85.7 % of eyes, and manifest refraction equivalent in ± 2.00 diopter range in 96.6% of eyes. Uncorrected visual acuity of 20/20 or better was reported in 37.1 % and 20/40 or better in 92 % of patients. Loss of the best spectacle corrected visual acuity of one line was observed in 13.4 % and 2 lines or more in 5.7 % of patients. Conclusion: In patients with moderate hyperopia and hyperopic astigmatism undergoing PRK the rate of regression was in ± 1 diopter range of surgeon’s intended correction in 85.7 % of patients at least six months postoperatively, which is in line with other studies findings. Keywords: Photorefractive keratectomy; Hyperopia astigmatism; Regression.