Theoretical analysis of image defocus with intraocular lens decentration.

We used a theoretical eye model to evaluate the effect on peripheral images when planoconvex, biconvex, and meniscus intraocular lenses (IOLs) decenter 1 mm or 2 mm upward or downward from the pupillary center. A light source was projected from an angle of 0, 20, 28, or 40 degrees downward to a retina with a radius of curvature of 11 mm. When the IOL was centered, the light focused at a single point on the retina. When the IOL was decentered, the light became more dispersed as the incident angle of the light increased. The most dispersion was noted with the meniscus IOL; the least with the biconvex IOL. Astigmatism and aberration, which IOL decentration increases, were thought to cause the image defocus. These results suggest that IOL decentration may affect the sharpness of peripheral images.