Human retinal pigment epithelial cells in the vitreous of the owl monkey

Cultured human retinal pigment epithelium was injected into the vitreous of owl monkeys. The epithelial cells were derived from either a foetal or an adult cell line. The five monkeys which were injected with cultured foetal cells developed substantial vitreal membranes and had retinal detachment by 2 weeks, whereas the five monkeys with cultured adult cells did not develop detachments within the period of investigation, and vitreal membranes were insubstantial. An electron-microscopic, immunohistochemical and autoradiographic study was conducted on these eyes to investigate in detail the behaviour and intraocular effects of the injected cells.