Learning curve of laser-assisted subepithelial keratectomy: influence on visual and refractive results.

摘要

PURPOSE: To study the effect of the learning curve of laser-assisted subepithelial keratectomy (LASEK) on the visual and refractive results. METHODS: This retrospective study comprised 56 eyes that had LASEK for myopia. The eyes were among the first 143 that had LASEK by the same surgeon with the same excimer laser and same nomogram. The 56 eyes were separated into 2 groups. Group 1 included the first 28 eyes to have LASEK by the surgeon. Group 2 comprised the last 28 eyes in the series whose refractive error could be matched with that in Group 1. The outcomes in the 2 groups were compared. RESULTS: The mean preoperative spherical refraction was -3.90 diopters (D) +/- 1.90 (SD) in Group 1 and -3.70 +/- 2.53 D in Group 2 (P = .2). There were no significant differences in preoperative cylinder or best spectacle-corrected visual acuity (BSCVA) between groups. The postoperative uncorrected visual acuity (UCVA) was significantly worse in Group 1 on 1 day and 7 days postoperatively (P = .02 and P .03, respectively); there was no significant difference at 1 month and 3 months. The safety index (postoperative BSCVA/preoperative BSCVA) and efficacy index (postoperative UCVA/preoperative BSCVA) were better in Group 2, although the difference was not statistically significant. The spherical refraction 3 months postoperatively was +0.50 +/- 0.83 D in Group 1 and +0.10 +/- 0.27 D in Group 2 (P = .02); 75.00% of eyes and 96.42% of eyes, respectively, were within +/-0.50 D of the intended correction (P = .01). Seven percent of eyes in Group 1 and no eye in Group 2 lost 2 or more lines of BSCVA. CONCLUSIONS: Results indicate that the outcomes of LASEK depend on surgeon experience. Thus, caution is advised when interpreting LASEK results without knowing the surgeon's level of experience.