Effect of simulated IOL tilt and decentration on spherical aberration after hyperopic LASIK for different intraocular lenses.

Purpose: To evaluate visual quality differences among intraocular lenses (IOLs) in patients with previous hyperopic laser ablations and to assess the impact of decentration and tilt of IOLs on visual quality.

Methods: An adaptive optics visual simulator was used to simulate the wavefront aberration pattern of one aberration-correcting IOL (AcrySof IQ SN60WF, Alcon Laboratories Inc) and two spherical IOLs with different amounts of positive spherical aberration (Akreos Adapt [Bausch & Lomb] and Triplato [AJL Ophthalmic]) in five situations-centered, 0.2 mm and 0.4 mm of decentration, and 2° and 4° of tilt-in two groups: simulated low hyperopic laser corneal ablation (low hyperopia group) and high hyperopic laser corneal ablation (high hyperopia group). Monocular distance visual acuity at 100%, 50%, and 10% contrast were measured.

Results: Ten eyes were evaluated. When the IOLs were centered, all IOLs obtained comparable results for the low hyperopia group, whereas for the high hyperopia group, the Akreos Adapt and AcrySof IQ SN60WF showed better visual acuity than the Triplato. When the IOLs were misaligned, for the low hyperopia group, the best visual acuity results were obtained with the Akreos Adapt and the most critical situation was at 0.4 mm of decentration. For the high hyperopia group, misalignments decreased visual acuity in a higher amount than for the low hyperopia group.

Conclusions: Our results suggest that the IOLs studied offer good visual quality when they are centered for both groups. However, tilt and decentration of monofocal IOLs have an impact on visual function in patients with hyperopic ablations. For these patients, the Akreos Adapt is the most robust to misalignments.