Massive periretinal proliferation (MPP) IV. Pre- and subretinal proliferation of glial tissue in experimental retinal detachment.

In experimental retinal detachment of the owl monkey eye, the formation of pre- and subretinal membranes was observed which typically had cellular connections to the retina proper. Based on light microscopic findings, it could be concluded that retinal cells grew out of the retina and built up the pre- and subretinal tissue. Electron microscopically these cells are glial cells (astrocytes) which grow out of the retina through focal interruptions in the internal limiting membrane and external limiting membrane. In the immediate area of outgrowth, Mueller cell processes participate in the formation of pre- and subretinal tissue.