Central Islands and Visual Outcomes of Phototherapeutic Keratectomy Using the Photorefractive Keratectomy Mode.

Abstract

To compare the rate of central island (CI) and visual acuity after phototherapeutic keratectomy (PTK) with and without the CI program. This retrospective study comprised 147 eyes of 89 consecutive patients (mean age ± SD, 71.1 ± 9.6 years) undergoing PTK with and without the anti-CI program [photorefractive keratectomy (PRK) mode and PTK mode] using the VISX Star S4 excimer laser system (Johnson & Johnson Vision, Santa Ana, US) for treatment of band keratopathy (BK) or granular corneal dystrophy (GCD). The rate of CI formation, defined as a steepening area of 3 D, 1.5 mm in diameter, on each corneal videokeratographer (ATLAS 9000; Carl Zeiss Meditec, Jena), and best spectacle-corrected visual acuity (BSCVA) were assessed 3 months after PTK. We found CI formation in 17 eyes (22%) in the PRK mode group and 45 eyes (73%) in the PTK mode group at 3 months postoperatively (P < 0.001, χ test). Postoperative logarithm of the minimal angle of resolution BSCVA was 0.10 ± 0.14 in the PRK group and 0.15 ± 0.13 in the PTK group (P = 0.019, Student t test). The rate of CI was 13 eyes (33%) with BK and 6 eyes (15%) with GCD in the PRK mode group and 25 eyes (83%) with BK and 20 eyes (71%) with GCD in the PTK mode group. The use of the anti-CI program for PTK significantly decreases the rate of CI formation and significantly improves BSCVA in post-PTK eyes, suggesting its viability for treatment of BK and GCD in clinical setting.