Abstract
Abstract: :
Purpose: Patients with corneal surface disease as well as refractive errors have the option of undergoing a phototherapeutic keratectomy (PTK) combined with a photorefractive keratectomy (PRK) procedure. This study investigates the changes in refraction and visual acuity (VA) in such patients at 3 and 6 months after the procedure. Methods: A retrospective study of 19 eyes from 14 patients was conducted. Their corneal surface diseases include map-dot-fingerprint dystrophy (MDFD), recurrent erosions (RE), superficial scars, and combinations of these. Myopia ranged from -7.50 D to -0.75 D. Astigmatism ranged from 0.00 D to +2.25 D. Preoperative uncorrected visual acuity ranged from 20/800 to 20/50. The corneal epithelium was removed with a 64 blade, and the treatment was performed using a VISX Star S3 laser. The cycloplegic refraction was treated in each case. Postoperative measurements were taken at 3 and 6 months. Paired t-test analyses of preoperative versus 3 months and preoperative versus 6 months were performed to determine significance of changes in refraction and visual acuity. Results: Preoperatively, mean myopia was -3.76 D (range -7.50 D to -0.75 D), mean astigmatism was +0.96 D (range 0.00 D to +2.25 D), and mean uncorrected VA was 20/303. At 3 months, mean myopia was -0.53 D (range -1.75 D to +0.75 D) (p < .001), mean astigmatism was +0.58 D (range 0.00 D to +1.25 D) (p = .05), and mean uncorrected VA was 20/22 (p < .001). At 6 months, mean myopia was -0.31 D (range -1.00 D to +0.75 D) (p < .001), mean astigmatism was +0.56 D (range 0.00 D to +1.25 D) (p = .05), and mean uncorrected VA was 20/22 (p < .001). Paired t-tests showed the results to be statistically significant at the .05 level. No patient lost any lines of vision. Conclusions: A statistically significant improvement in both refraction and uncorrected VA was seen in the subjects at both 3 and 6 months postoperatively. The combination PTK/PRK procedure thus offers an effective and convenient solution for patients with corneal surface disease and moderate myopia.
Keywords: refractive surgery: PRK • cornea: clinical science • refractive surgery