The purpose of this project is to develop synthetic polymers and therapeutic devices for use in opthalmology. A new hydrophilic scleral buckling material for retinal detachment surgery has been developed. It consists of a crosslinked copolymer of 2-hydroxyethyl acrylate with methyl acrylate. It is a soft and strong in the dry state as well as when swollen in water or physiological fluids. Experimental scleral buckling in rabbit eyes points to the high tolerance and ideal softness of this material which can withstand the compression of overlying sutures. The implant absorbs antibiotics and releases them into the surgical site to diminish the incidence of early infection. A silicon rubber balloon that can be implanted subconjunctivally in experimental animals has been developed. The balloon is used as a depot for lipophilic drugs which are delivered at a constant rate to the eye. It can be refilled in situ for prolonged treatment. An animal model of ocular malignancies, transplanted Greene melanoma in the uvea of rabits, in being used to test sustained delivery chemotherapy with nitrosourea derivatives. A great diversity of contact lenses, both hard and soft, hydrophilic and hydrophobic, are being introduced with increasing frequency for optical correction as well as for therapeutic use in corneal diseases and in aphakia. This laboratory will investigate the oxygen permeability and other physicochemical and physiological properties of the available lenses.