Evaluation of Retinal Image Quality in an Eye with a Multifocal Intraocular Lens Using a New Point Spread Function Analysis System

Abstract

Abstract: : Purpose: To evaluate retinal image quality in an eye with a multifocal intraocular lens (IOL) using a new point spread function (PSF) analyzer (Topcon. Co, Tokyo, Japan). Methods: The subject is the right eye of a 27–year–old female who underwent lens aspiration with refractive multifocal IOL (SA40NB, AMO, CA) implantation. The additional power for near focus of this IOL is about 2.6 diopters (D) at the spectacle plane. Distance vision was 20/20 and near vision was 20/40 in the eye with best distance correction. PSF and modulation transfer function (MTF) at various defocus positions (0 to –3.5, 0.25 D each) were evaluated with a new PSF analyzer using an artificial pupil(Φ=2, 4, 6 mm)in mydriasis. The retinal images of Landolt’s rings at various defocus positions were simulated from the PSF by convolution of the originals with 100% contrast. Results: The PSF image spread with over 1.5 D of defocusing. The MTF was the highest at 0 D (best distance correction) then decreased with defocusing, was the lowest around –1.75 D, and increased and reached the second peak at –2.75 D. The contrast of the simulated retinal images decreased with pupil diameter at 0 D and around –2.5 D. Conclusions: The retinal image quality in an eye with a multifocal IOL can be objectively evaluated clinically using a new PSF analyzer, and the results are comparable to the optical design of the IOL.

Keywords: contrast sensitivity • refractive surgery: optical quality • refractive surgery: other technologies