A New Approach of Aspheric Intralamellar Keratoprostheses Optic Design made with poly(2-hydroxy ethylmethacrylate) Hydrogel.

Abstract

Keratoprosthesis (KPro) is a surgical procedure largely confined to end-stage corneal blindness correction, where artificial cornea substitutes the native tissue. Though the problem of bio integration was addressed partially by strategic utilization of synthetic polymers and native tissue, major challenges like optical performance and design-associated post-operative complications of KPro were overlooked. Herein, a novel intralamellar KPro design is conceptualized to address these challenges using a light-transparent poly(2-hydroxy ethylmethacrylate) (pHEMA) hydrogel with good shape memory. pHEMA-based optics' theoretically modelled refractive surfaces for both phakic and aphakic conditions were investigated against the standard Navarro model and optimized to new aspheric geometries having high optical functionality utilizing the Zemax OpticStudio software. The optical clear aperture size standardized achieved a 15 % improvement in the illumination field. The introduction of asphericity on the two refractive surfaces of the optic on both models resulted in substantial improvements in the spot spread confinement on the retina, spatial resolution, and Seidel aberration. The design simulation study shows that the developed materials' optical characteristics coupled with newly optimized refractive surface geometries can indeed deliver very high visual performance. Furthermore, the procedure can be adapted to analyze and optimize the optical performance of a KPro, intraocular lens, or contact lens.