Posters

Contrast sensitivity with a small aperture IOL evaluated with an adaptive optics instrument

Poster Details

First Author: S.Manzanera SPAIN

Co Author(s):    J. Marin   P. Artal           

Abstract Details

Purpose:

The concept of a small aperture to extend depth of focus can be implemented in an intraocular lens with an embedded mask. This IOL would be implanted in the non- dominant eye. We studied the contrast sensitivity function (CSF) in subjects with a small aperture projected into one eye by using an adaptive optics vision analyzer.

Setting:

Laboratorio de Optica, Universidad de Murcia, Murcia, Spain Servicio de Oftalmología, Hospital Virgen de la Arrixaca, Murcia, Spain

Methods:

We used a research prototype binocular adaptive optics visual analyzer to measure the binocular CSF. The instrument allows for modifying the eye's optical aberrations in the two eyes simultaneously. It incorporates two liquid-crystal spatial light modulators, one for wavefront shaping and the other to create the artificial aperture. A micro-display presents gratings for visual testing. A Bayesian adaptive method was used to measure the CSF accurately with duration of the test within 5 minutes (Lesmes et al., J. Vision, 10, 1, 2010). CSFs were measured binocularly in four normal subjects at best focus for distance visual stimuli and with both pupil set to 3 mm diameter and one set to 3 mm and the other (non-dominant) to 1.44 mm. The mean luminance of the screen was near mesopic conditions (0.5 cd/m2).

Results:

There was not statistical difference between the binocular CSFs for the reference case (3 mm each eye) and the case with the small aperture in the non-dominant eye (3-1.44 mm). However, the average CSF was slightly worse for the latter case at both low and high spatial frequencies. Although the used pupil diameter was slightly larger than the one proposed for a small aperture IOL (1.44 versus 1.36 mm), it is expected that the results would be within the similar range.

Conclusions:

IOLs with an embedded small aperture mask implanted in the non-dominant eye would produce a binocular contrast sensitivity similar to the case with normal pupils even at mesopic conditions. This can be a viable alternative approach to induce depth of focus without compromising binocular contrast sensitivity. FINANCIAL INTEREST: One of more of the authors... receives consulting fees, retainer, or contract payments from a company producing, developing or supplying the product or procedure presented