Aspheric And Spherical Pseudophakic Performance With And Without Glare: Optical Ensemble Analysis

Abstract

Purpose: : Pseudophakic optical performance with and without glare depends on intraocular lens (IOL) optical design and optic material properties. Optical ensemble analysis (OEA) was used to determine how glare affects the performance of aspheric vs. spherical IOLs.

Methods: : Previously validated Monte Carlo analysis [Zhao H. Opt Lett 2009;34:7-9] was used to compute the overall optical performance of 4 groups of 100 pseudophakes, each with a different commonly-used IOL: (G1) high Abbe number (low chromatic dispersion) acrylic IOLs fully-correcting pseudophakic SA; (G2) lower Abbe number acrylic IOLs partially-correcting pseudophakic spherical aberration (SA); (G3) silicone IOLs correcting only IOL SA; and (G4) silicone spherical IOLs. Modulation transfer functions (MTFs) for distance vision were computed over clinically-relevant values (normal distribution) of an ensemble of ocular parameters with and without an annular glare source used previously in human studies (1.1^o eccentricity; 0.2^o angular extent).

Results: : Aspheric IOLs improve pseudophakic visual performance under glare conditions. Populations G1, G2 and G3 all outperformed the spherical IOL G4 group. Mesopic performance improvement for the G1 population was potentially clinically-significantly better than G4, but not for the G2 and G3 populations. Standard deviations were lowest in groups G3 and G4, followed by populations G1 and G2. There was some overlap in simulated optical outcomes with glare for the three different aspheric IOL groups.

Conclusions: : Simulated optical outcomes with glare are consistent with published laboratory and clinical findings. All three aspheric IOL populations were more glare resistant under mesopic light conditions than the spherical IOL group, although the significance level differed between the groups. Aspheric pseudophakic group G1 (lower chromatic dispersion optic material; full correction of pseudophakic SA) had the best performance under glare conditions.

Keywords: intraocular lens • contrast sensitivity • refractive surgery: optical quality