Posterior vitreous separation and retinal detachment induced by macrophages

Macrophages, which migrate into the vitreous in conditions such as vitreous hemorrhage and penetrating ocular injury, may contribute to the development of intravitreous cellular proliferation and posterior vitreous separation. To investigate this possibility, activated macrophages were harvested from the peritoneal cavity and injected into the vitreous of rabbits. As early as 8 days after macrophage injection, posterior vitreous separation and glial epiretinal membrane formation began to occur. Two weeks after injection, vitreous strands that approached the optic disc and medullary rays were evident; fibroblasts proliferated over the disc or rays and induced retinal detachment. These findings support the hypothesis that macrophages in the vitreous may, in part, mediate cellular proliferation and posterior vitreous separation.