Wavefront-guided photorefractive keratectomy after radial keratotomy in nine eyes

PURPOSE: To investigate the refractive outcomes of wavefront-guided photorefractive keratectomy (PRK) in patients with previous radial keratotomy (RK). METHODS: This study is a retrospective review of consecutive cases from August 2004 until February 2007 of PRK after RK. The VISX STAR S4 excimer laser was used. Visual acuity, manifest refraction, and slit-lamp microscopy were reviewed preoperatively and 3 and 12 months postoperatively. RESULTS: Nine eyes, five hyperopic and four myopic, of six consecutively treated patients were evaluated. Myopic spherical equivalent refractive treatments averaged -2.08 diopters (D) (range: -0.80 to -3.36 D) and hyperopic treatments averaged +2.20 D (range: +1.28 to +3.12 D). No eyes lost any lines of Snellen best spectacle-corrected visual acuity (BSCVA) and three (33%) eyes gained one line of BSCVA. Two (22%) eyes showed grade 0.5 level haze (not in the visual axis) and the remaining seven eyes showed no haze. Seven (77%) of nine eyes were within ±0.25 D of the targeted spherical equivalent refraction at 3 months postoperative. Six (66%) of nine eyes had ≥0.50 D (range: +0.50 to+2.25) of astigmatism prior to PRK and all astigmatic errors were significantly reduced, with the highest residual astigmatic error of 0.75 D in one eye and 0.50 D in two eyes. CONCLUSIONS: Wavefront-guided PRK after RK for myopic, hyperopic, and astigmatic refractive errors targeting emmetropia in six eyes and myopia in three eyes yielded accurate refractive outcomes in this consecutive series. Three (33%) of nine eyes gained one line of BSCVA with no eyes losing BSCVA. Seven of nine eyes were within ±0.25 D of targeted spherical equivalent refraction at 3 months postoperative.