Artificial vitreous replacements

Vitreoretinal pathologies remain the significant leading cause of blindness, after cataract, throughout the world. Biomaterials as a whole, and vitreous substitutes in particular, have had a major role to play in vitreoretinal surgery. History has witnessed the advent of vitreous substitutes from collagen and hyaluronic acid to gases, silicone oils and perfluorocarbon liquids and now to polymer hydrogels. Such a long list only underscores the fact that we have been found wanting in our quest for an ideal vitreous substitute. This review focuses on the merits and demerits of various vitreous substitutes, which have been tried to date, clinical as well as experimental. The properties required of an ideal substitute and the performance of the vitreous substitutes with respect to these criteria have been described. Finally, the concluding note dwells on the future directions for biomaterial research in the posterior segment of the eye and undermines the role of tissue engineering in vitreoretinal regeneration.