Introduction For sometime now, we have been intrigued with the possibility of treating retinal detachment by placing an inert substance in the suprachoroidal space in order to elevate the choroid over the area of the tear, draining the subretinal fluid and treating the retina and choroid with light coagulation. In order to further this idea, it was decided to test the tissue reactions of various types of silicone rubbers, Dow Corning Silastic, in the suprachoroidal space of the dog eye. Previously, one of us1had attempted to insert polyethylene tubing and polyvinyl sponge into the suprachoroidal space after coagulating the choroid lightly with diathermy. The incidence of choroidal rupture and vitreous loss was too great to be practical. Recently, McDonald et al2have placed silicone implants (Dow Corning Silastic 372) in the suprachoroidal space. These implants had a steel wire connected to them and were arranged so that