Effects of Superficial Keratectomy in Peripheral Hypertrophic Subepithelial Corneal Opacification on Front and Back Corneal Astigmatism

Abstract

ABSTRACT Purpose To evaluate changes of anterior and posterior corneal astigmatism after superficial keratectomy in peripheral hypertrophic subepithelial corneal opacification (PHSCO). Methods Patients with PHSCO, who had received superficial keratectomy with mitomycin C 0.02%, were included in this retrospective study. Scheimpflug imaging of the cornea (Pentacam®, Oculus, Wetzlar, Germany), best-corrected visual acuity (BCVA) and objective refraction were determined preoperatively and 3 months after superficial keratectomy. Results Fifteen eyes of 15 patients (age: 55 ± 16 years; range: 36–82 years) were included. The mean preoperative BCVA was logMAR 0.4 ± 0.2 and improved to logMAR 0.21 ± 0.3 (p < .01) postoperatively. The median preoperative astigmatism of the anterior corneal surface was 4.67 ± 2.4 D (range: 0.9–13.2 D) and decreased to 1.4 ± 0.4 D (range: 0.8–2.3 D) 3 months after surgery. The median astigmatism of the posterior corneal surface was 0.6 ± 0.5 D (range: 0.1–2.2 D) before surgery and decreased to 0.3 ± 0.2 D (range: 0–0.7 D) 3 months after surgery. Conclusion Superficial keratectomy reduces anterior corneal astigmatism more than posterior corneal astigmatism in patients with PHSCO. Furthermore, a myopic shift and corneal steepening in the peripheral and mid-peripheral cornea was observed after removal of the subepithelial corneal opacification spots.