Effect of intraocular lens decentration on image quality tested in a custom model eye.

PURPOSE: To evaluate the effect of intraocular lens (IOL) decentration on optical aberrations with different IOL designs.

SETTING

Visual Optics and Biophotonics Laboratory, Instituto de Óptica, Consejo Superior de Investigaciones Científicas, Madrid, Spain.

DESIGN

Experimental study.

METHODS

The following 18 aspheric IOLs immersed in a physical model eye were measured using a laser ray-tracing aberrometer: 10 Vivinex XY1 with spherical aberration correction of -0.18 μm (V-0.18), 4 Tecnis 1P ZCB00V with spherical aberration correction of -0.27 μm (T-0.27), and 4 Acrysof 1P SN60WF with spherical aberration correction of -0.17 μm (A-0.17). The optical aberrations were evaluated with the IOL on axis and 0.4 mm and 0.7 mm laterally decentered. The laser ray tracing-measured aberrations were compared with aberrations estimated using virtual ray tracing. Retinal image quality was evaluated from the modulation transfer function (MTF) and visual Strehl ratio.

RESULTS

Wave aberration measurements of the same IOL were highly repetitive (deviation <0.02 μm). Astigmatism and coma increased with decentration at a rate of 0.18 μm/mm and 0.19 μm/mm for the V-0.18, 0.20 μm/mm and 0.32 μm/mm for the T-0.27, and 0.26 μm/mm and 0.39 μm/mm for the A-0.17, respectively. The 0.7 mm lateral decentration decreased the visual Strehl ratio by 2.23 times for the V-0.18, by 2.8 times for the T-0.27, and by 3.2 times for the A-0.17. The V-0.18 showed the highest MTF and visual Strehl values for all centration values.

CONCLUSIONS

Lateral decentration resulted in decreased retinal image quality. The V-0.18 was the most immune design to optical degradation caused by decentration.