Development of an injectable intraocular lens for preservation of accommodation

Purpose. To develop a surgical technique for removal of the natural cataractous lens and replace within the capsular bag a synthetic, hydrophilic, nonrigid, intraocular lens that would have the ability to accommodate. Method. Various homo- and copolymer hydrogels were made from appropriate aqueous mixtures of hydroxyethylacrylate, N-vinyl pyrrolidone, diacrylate polyethyleneglycol (PEG), and tetraacrylate PEG. These precursors were reacted in the presence of a catalytic amount of photoinitiator and chain transfer agent. The reaction mixture was illuminated using an argon ion laser at 514 nm to convert the injectable liquid precursor to a hydrogel. Optical, mechanical, density, and equilibrium swelling properties of homo- and colymers were studied. Results. In-situ polymerization and/or gelling of hydroxyethylacrylate was least efficient and most exothermic. Diacrylate and tetraacrylate PEG reacted with minimum heat of reaction and unreacted precursor (measured by low-angle laser light scattering). Optical, mechanical, density and equilibrium swelling were a function the degree of crosslinking. Conclusions. Di- and tetraacrylate terminated PEG gelled in the presence of a biocompatible photoinitiator and argon ion laser seems to be worthy of further investigation as an injectable intraocular lens with accommodative properties.