Posters

Monovision using plus and minus spherical aberration values

Poster Details

First Author: S.Tsuruoka JAPAN

Co Author(s):    K. Ohnuma   T. Noda           

Abstract Details

Purpose:

To evaluate the efficacy of a new monovision method by adjusting the spherical aberrations of eyes with an aspherical intraocular lens (IOL).

Setting:

Center for Frontier Medical Engineering, Chiba University

Methods:

Spherical aberration and coma can extend the depth of field. Further, the minus and plus values of spherical aberration can control the direction of the extent of the depth of field. We investigated the effects of spherical aberration on monovision using an image simulator and a 3-dimensional display. To simulate the images on the retina from each visual distance, software was developed to calculate the point spread functions (PSFs) according to the distance and to vary the amount of aberration and simulate retinal images by convolution of the object with the PSFs. Because the method using the optical design software is impractical, by changing the amount of spherical aberration plus to minus 0.5 micron, adequate conditions can be identified. Further, to check the three-dimensional view, images of the left and right eyes were simulated and displayed on an autostereoscopic display of the Fujifilm® FinePix REAL 3D V3. Determining if part of an image floats slightly from the plane can be ascertained by changing the disparity angle of a subject with a normal eye and stereo-vision.

Results:

Different results have been obtained by changing the pupillary diameter and the amount of spherical aberration. Two representative results are shown. In a case with a 2- to 3-millimeter pupillary diameter, the effect of aberration is small. Based on the depth of field, as a result of the small pupillary diameter, monovision is established with a 1.0-diopter difference in the dioptric power between the left and right eyes. A greater power difference degrades the intermediate image. However, with a 4- or 5-millimeter pupillary diameter, the near vision focused on 40 centimeters with minus 0.3 micron of spherical aberration and distance vision at 2 meters with plus 0.3 micron, a wide range of monovision is expected with 1.2 decimal visual acuity at near and distance ranges and 0.7 at the intermediate range. Further, a stereoscopic view in near vision was established in stereo disparity from 100 to 200 seconds.

Conclusions:

Monovision within a power difference of 1 D is adequate in patients with 2- to 3-millimeter pupils. With larger pupils of 4 to 5 millimeters, monovision with a power difference of 2 D is possible by adding minus spherical aberration to the near vision and plus spherical aberration to the distance vision. FINANCIAL INTEREST: NONE