Posters

Binocular contrast sensitivity for different combinations of spherical aberration and monovision

Poster Details

First Author: P.Artal SPAIN

Co Author(s):    S. Manzanera   E. Villegas   M. Haller   J. Marin           

Abstract Details

Purpose:

The use of light adjustable intraocular lenses (LALs) allows to induce controlled amounts of spherical aberration and monovision as a practical approach to increase depth of focus. We studied binocular contrast sensitivity for different possible combinations that can be implemented to determine the optimum solution.

Setting:

Laboratorio de Optica, Universidad de Murcia, Murcia, Spain

Methods:

We used a laboratory prototype of a binocular Adaptive Optics Visual simulator. This is an instrument to perform visual testing with full control of the optical aberrations induced in the patient’s eye non-invasively. Binocular contrast sensitivity was measured in eight subjects with paralyzed accommodation, 4-mm artificial pupil, white light for 4 combinations of spherical aberration (SA) in each eye: 0,0; 0,-0.2; -0.2,-0.2; 0.2,-0.2 (in microns). The dominant eye was kept at best focus for distance and the non-dominant eye was induced a relative defocus from 0 to 2.5 D (in steps of 0.5 D).

Results:

Binocular contrast sensitivity decreased with induced disparity for all cases. The highest values were obtained for all defocus values with the (0,0) and (0,-0.2) combinations. The induction of SA in both eyes reduced contrast sensitivity around 50% as compared with the case with one eye aberration-free. For all combinations, there was binocular summation for defocus disparity less than 1.5 D and appeared a moderate inhibition when the induced defocus in one eye was over 1.5 D. These results are in agreement with clinical data in patients bilaterally implanted with LALs, where one eyes was set to emmetropia and the fellow eye received an aspheric treatment to induce negative SA ranged around -0.2 microns (for a 4-mm pupil).

Conclusions:

We used an adaptive optics instrument to evaluate binocular contrast sensitivity for different combinations of monovision and asphericity. The optimum results in terms of binocular summation and contrast sensitivity were obtained with one eye set for distance and the fellow with defocus (monovision) below 1 D and induced negative spherical aberration. This condition can be implemented by using LALs bilaterally in cataract patients.

Financial Disclosure:

One or more of the authors receives consulting fees, retainer, or contract payments from a company producing, developing or supplying the product or procedure presented