To evaluate changes of anterior and posterior corneal astigmatism after superficial keratectomy in peripheral hypertrophic subepithelial corneal opacification (PHSCO).
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 three months after superficial keratectomy.
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 < 0.01) 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) three 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) three months after surgery.
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.