Platelet-induced vitreous membrane formation.

The role of extravascular coagulation in vitreous membrane formation was investigated in rabbits and owl monkeys. Eyes injected with platelet-poor plasma did not develop vitreous membranes. In contrast, the injection of platelet-rich plasma and gel-filtered platelet preparations into the vitreous cavity resulted in immediate membrane formation. These vitreous membranes were only slowly and incompletely removed by a low-grade histiocytic response. Membrane formation could be inhibited by prior incubation of the platelet preparations with acetylsalicylic acid or by homogenizing the platelets. Intact platelets with normal functional capacity appear to be important in the instantaneous formation of membranes when blood components escape into the vitreous cavity.