Spherical aberration and depth of focus in eyes implanted with aspheric and spherical intraocular lenses: a prospective randomized study

Abstract

Purpose: To compare distance-corrected, near, and intermediate visual acuities as a measurement of depth of focus and spherical aberration of eyes implanted with aspheric and spherical intraocular lenses (IOLs).

Design: Randomized prospective study.

Participants: One hundred twenty eyes of 60 patients with bilateral cataract implanted with 3 IOL models (AcrySof IQ, AcrySof SN60AT [Alcon Laboratories, Fort Worth, TX], and Sensar AR40 [Allergan Surgical, Irvine, CA]).

Methods: Pupil diameter was analyzed by using a Colvard pupillometer (OASIS Medical, Inc., Glendora, CA) under photopic, mesopic, and scotopic conditions. Distance (6 m), intermediate (1 m), and near (0.33 m) visual acuities were measured with distance correction in place 90 days after surgery. Wavefront analysis (LadarWave; Alcon Laboratories) was performed using 5-mm and measured photopic pupil diameter at 30 and 90 days after surgery.

Main outcome measures: To evaluate spherical aberration and depth of focus (by means of distance-corrected near and intermediate visual acuity) in patients implanted with aspheric and spherical IOLs.

Results: Photopic pupil sizes in each group were similar at 30 days after surgery. At 90 days after surgery, mean logarithm of the minimum angle of resolution distance-corrected near visual acuity (+/-standard deviation [SD]) was 0.50+/-0.20 in the AcrySof IQ group, 0.38+/-0.17 in the AcrySof SN60AT group, and 0.45+/-0.16 in Sensar AR40 group. Mean spherical aberration values (+/-SD) were 0.03+/-0.05 microm in the AcrySof IQ group, 0.24+/-0.04 microm in the AcrySof SN60AT group, and 0.14+/-0.07 microm in the Sensar AR40 group. The AcrySof IQ group showed a statistically significant lower induction of spherical aberration and worse distance-corrected near visual acuity. The AcrySof SN60AT group showed statistically significant higher mean spherical aberration values and better distance-corrected near and intermediate visual acuity.

Conclusions: The reduction of total spherical aberration after aspheric IOL implantation may degrade distance-corrected near and intermediate visual acuity.