A Comparison of LASIK Versus PRK Enhancement Outcomes in Eye With Prior Cataract Surgery

Cataract surgery continues to evolve with increasing levels of precision through the development and introduction of new technologies. Despite these advances, unexpected visual outcomes attributable to residual refractive error still occur. Additional "enhancement" procedures to the cornea can treat this residual refractive error to achieve a satisfactory outcome. Two frequently employed excimer laser enhancement procedures include laser in-situ keratomileusis (LASIK) and photorefractive keratectomy (PRK). While both of these procedures are widely accepted as safe and effective in treating refractive error, there is a paucity of data comparing the two as enhancements in the post-cataract population. The purpose of this study was to investigate visual and refractive parameters in the pre- and post-enhancement setting on post-cataract surgery patients to compare the effectiveness of both excimer laser-enhancement treatments.

This study examined patients that underwent post-cataract extraction excimer laser enhancement surgery targeted for emmetropia (±0.50 D). The setting was a private, tertiary surgery center. Refractive enhancement procedures were performed by 3 different surgeons. Post-enhancement uncorrected distance visual acuity (UDVA) and manifest refraction spherical equivalent (MRSE) was recorded for all available follow-ups and compared for both groups.

This study included 822 post-cataract enhanced eyes (491 LASIK; 331 PRK). For patients with at least six months follow up, mean UDVA was 0.05 ± 0.13 logMAR in LASIK-enhanced patients and 0.15 ± 0.20 in PRKenhanced patients. Mean absolute value MRSE was 0.22 ± 0.36 and 0.48 ± 0.62 for LASIK- and PRKenhanced patients at or beyond six months, respectively. A total of 330 (67%) of LASIK-enhanced patients achieved 20/20 or better post-enhancement UDVA, compared to 142 (43%) PRK-enhanced patients. Categorized by pre-enhancement UDVA, LASIK-enhanced patients showed significantly better post-enhancement UDVA than PRK-enhanced patients, except in those with pre-enhancement vision of 20/20 or better, or those worse than 20/50. LASIK-enhanced virgin corneas had mean post-enhancement of 0.05 ± 0.14 UDVA compared to 0.13 ± 0.19 UDVA in PRK-enhanced virgin cornea patients.

LASIK provides better and more predictable outcomes in UDVA than PRK in post-cataract enhancement patients, even when categorizing patients by their pre-enhancement visual acuity, prior ocular procedures, and allowing for sufficient time for healing and stabilization of the cornea.