To compare visual and optical outcomes of pupil-centered vs vertex-centered ablation in patients undergoing laser-assisted in situ keratomileusis (LASIK) for hyperopia.
Randomized, double-masked, prospective, single-center trial.
Setting: Institutional practice. Study population: Sixty eyes of 30 patients with low and moderate hyperopia. Intervention procedure: Eyes underwent LASIK (Allegretto excimer laser). In 30 eyes, the ablation was centered on the pupil, while in the 30 other eyes the ablation was centered on the corneal reflex. Main outcome measures: Primary outcome measure was the safety index. Main secondary outcome measures were efficacy index, manifest refraction, uncorrected visual acuity, best spectacle-corrected visual acuity (BCVA), and ocular high-order aberrations for a 6-mm pupil size.
At 3 months postoperatively, the safety index was 0.99 ± 0.04 in the pupil-centered group and 0.99 ± 0.08 in the vertex-centered group (P = .97). The efficacy index was also similar for both groups: 0.96 ± 0.05 in pupil-centered eyes and 0.93 ± 0.09 in vertex-centered eyes (P = .31). Optical aberrations were similar for pupil-centered and vertex-centered eyes. Considering only eyes showing large pupil decentration, we found a tendency for better visual results in favor of pupil-centered eyes in terms of safety index and a slight but significant increase of coma in vertex-centered eyes.
LASIK is an effective procedure for treatment of hyperopia. Pupil-centered and vertex-centered treatments provide similar visual and optical outcomes. However, in eyes showing large temporal pupil decentration, pupil-centered ablation seemed to produce a lower amount of coma and, as a consequence, a reduced loss of BCVA compared with vertex-centered patients.