A contralateral, randomized comparison of optimized prolate ablation and conventional LASIK for myopia with the NIDEK excimer laser platform.

PURPOSE To compare the refractive, visual acuity, topographic, and spherical aberration outcomes of LASIK using the Quest excimer laser platform with the optimized prolate ablation (OPA) profile (NIDEK Co Ltd) in one eye and conventional ablation profile in the fellow eye of the same patient. METHODS Thirty-seven myopic patients underwent LASIK bilaterally, with one eye randomized to receive OPA ablation (-3.88±1.42 diopters [D], range: -1.53 to -7.50 D) and the fellow eye to receive conventional ablation (-3.89±1.37 D, range: -1.75 to -7.00 D). Independent and paired t tests were used for testing differences between groups at last postoperative follow-up (6 or 12 months). RESULTS Postoperatively, 97% (32/33) of OPA eyes and 94% (31/33) of conventional eyes saw 20/20 or better without correction (P>.05). No eyes lost 2 or more lines of distance corrected visual acuity. Manifest refraction spherical equivalent was -0.16 D in the OPA group and -0.05 D in the conventional group (P>.05). Ocular spherical aberration was -0.003 μm in the OPA group and +0.102 μm in the conventional group (P<.05). Corneal asphericity was statistically lower after OPA (0.07±0.26) compared to conventional ablation (0.30±0.26) (P<.001). The mean programmed optical zone and achieved postoperative horizontal diameter of the effective optical zone were statistically significantly larger in the OPA group (P<.05). CONCLUSIONS Postoperative visual acuity and refractive outcomes were similar between groups. Laser in situ keratomileusis using the OPA profile for the correction of myopia induced significantly less corneal and ocular spherical aberration, resulted in normal postoperative asphericity in 94% of eyes, and larger horizontal diameter of the effective optical zone compared to the conventional profile.