Abstract
Purpose:
Implantation of aspheric intraocular lenses (IOL) in cataract surgery results in improved contrast sensitivity compared to spherical IOL. We conducted this meta-analysis study to evaluate the influence of the implantation of aspheric intraocular lenses (IOL) compared to spherical IOL on wavefront properties in a pseudophakic eye.
Methods:
Peer-reviewed literature was systematically searched in Medline, EMBASE, Web of Science, BIOSIS and the Cochrane library according to the Cochrane Collaboration method to identify randomized controlled trials (RCT) on the subject. The inclusion criteria were RCTs on cataract surgery comparing the use of aspheric versus spherical monofocal IOL implantation that assessed visual acuity, contrast sensitivity or quality of vision. As secondary outcome ocular wavefront analysis was summarized. Here we present data on wavefront analysis. The data were grouped for different pupil sizes (ps.) and for the different aspheric IOL models evaluating higher-order aberrations, spherical aberration, coma and trefoil described in Zernike polynomials. Effects were calculated as standardized mean differences (Hedges’ g) and were pooled using random-effect models.
Results:
Thirty-four studies out of forty-three published studies provided data for wavefront analysis. Aspheric IOL implantation decreases ocular spherical aberration in comparison to spherical IOL implantation (ps. 4mm: ES (effect size)= -1.78 [-2.40; -1.15] 95% confidential interval, ps. 5mm: ES= -2.19 [-2.69;-1.69], ps. 6mm: ES= -2.03 [-2.46;-1.59]). Ocular coma was slightly smaller after aspheric IOL implantation for a ps. of 6mm (ES= -0.24 [-0.40;-0.08]), no effect was found for 4mm or 5mm. For ocular trefoil measurements, a significant effect was calculated only for a pupil size of 4mm (ES= -0.47 [-0.87;-0.07]), but not for 5mm or 6mm. Higher-order aberrations were smaller after aspheric IOL implantation (ps. 4mm: ES= -0.61 [-1.10; -0.13], ps. 5mm: ES= -0.63 [-0.93; -0.34], ps. 6mm: ES= -1.12 [-1.47;-0.77]).
Conclusions:
Aspheric monofocal IOL implantation results in less ocular spherical aberration and less ocular higher-order aberrations compared to spherical IOLs. This might explain the better performance in contrast sensitivity of aspheric compared to spherical IOLs.
Keywords: 445 cataract •
567 intraocular lens •
630 optical properties