Comparative Study of Retinal Image Quality in Eyes With Monofocal and Multifocal Intraocular Lens Using the Point Spread Function Analyzer

Abstract

Abstract: : Purpose: To evaluate and compare retinal image quality in eyes with monofocal and multifocal intraocular lens (IOL) using a new point spread function (PSF) analyzer. Methods:Eight eyes that underwent lens aspiration with multifocal IOL (SA40NB, AMO) implantation and eight eyes with a monofocal IOL (AR40e, AMO) were studied. A point light source was projected onto the eyes with IOLs, the reflected images at the retina were captured by the charge–coupled device, and the PSFs were analyzed. Modulation transfer functions (MTFs) of the optical systems were obtained through equal–sized apertures as entrance and exit pupils and the phase transfer functions (PTFs) through unequal–sized apertures. The retinal images of the Landolt’s rings at various defocus positions were simulated from the PSFs by convolution of the originals with 100% contrast. Results: In eyes with multifocal IOLs, the average contrast value of the simulated retinal images of the Landolt’s rings was the highest at 0 D (best distance correction) then gradually decreased with defocusing, was the lowest around –1.0 D, and increased and reached the second peak at –2.5 D. In eyes with a monofocal IOL, the average peak contrast value at 0 D was higher than that of multifocal IOLs, and the contrast decreased sharply with defocusing. Conclusions: The difference in retinal image quality at various defocus positions in eyes with monofocal and multifocal IOLs can be objectively evaluated using a new PSF analyzer, and the results are comparable to the optical designs of each IOL.

Keywords: contrast sensitivity • optical properties • visual acuity