Abstract
Abstract: :
Purpose: To determine the optimum design of the Acufocus Corneal Inlay (ACI), a thin, micro–perforated artificial aperture intended to restore near vision in presbyopic patients. Methods: Computer–aided geometric optical modeling (Zemax) was used to predict the performance of the ACI in an emmetropic schematic eye. The ACI design variables studied were the inside diameter and the luminous transmission through the annulus. Modulation Transfer Function (MTF) plots were produced to estimate the visual performance with the inlay, using MTF volumes as an estimate of resolving power to compare ACIs of different dimensions. Computer–aided diffraction analysis (Matlab) was used to generate the Point Spread Function (PSF) of a nominal eye with various inlay perforation patterns. PSF plots for a regular hexagonal, regular rectangular, and randomized array of the micro–perforations in the ACI were produced to compare the effects of diffraction through different perforation patterns. Results: An ACI with an inside diameter of 1.25 mm to 1.8 mm and a light transmission of 10% or less was predicted to provide J3 or better near vision and distance vision of 20/20 or better in an emmetropic presbyope. Hole patterns with a regular spacing produced a patterns of spots surrounding a point source (e.g. street light). When the perforation pattern was modified so that the hole locations were randomized, patterned diffraction effects were minimized. Conclusions: The ACI can be used to provide functional near vision in the emmetropic presbyope, without compromising distance vision. Randomizing the pattern of micro–perforations in a corneal inlay is effective in minimizing any visual impact from diffraction produced by these pores.
Keywords: refractive surgery: optical quality • computational modeling