Vitreous Substitutes and Drug Delivery Using the Vitreous

Abstract

After removal of the native vitreous during vitreoretinal surgery, an adequate replacement is required to ensure ocular homeostasis. To mimic the functions of the native vitreous body, the design of an ideal replacement material is based on the optical, physicochemical and physiological properties of the healthy, juvenile vitreous body. Current clinically used tamponades including oils, gases and semifluorinated alkanes cannot meet the requirements of a suitable vitreous substitute due to fundamentally different characteristics, leading to a variety of postoperative complications. Given these challenges, there has been a call for a critical re-evaluation of materials used as vitreous substitutes. Here, hydrogels represent an authentic replacement option due to their similarity to the native vitreous. Beyond mere replacement, vitreous substitutes can also be tailored as drug delivery systems for the rapid or sustained release of therapeutic agents to address various ocular pathologies.