Wound healing after xenon arc photocoagulation in the rabbit retina. Identification of the proliferating cells in the lesion by light and electron microscopic autoradiography using 3h-tymidine.

Processes of the scar formation after Xenon arc photocoagulation in the rabbit retina were studied. Electron microscopic autoradiography using tritiated thymidine identified the proliferating cells in the reparative tissue as Müller's cell, retinal pigment epithelial cell, and choroidal fibroblast. The Müller cell and the retinal pigment epithelial cell, which proliferated in and around the lesion, formed the retinal scar tissue, while the proliferated fibroblast in the choroid did not participate in the formation of the retinal scar. The Müller cells extended their cytoplasmic processes toward the pigment epithelium to form the interdigitating adhesion. This process seemed to be secondary step of the scar formation following the cell proliferation. Migration of cells from the edge of the lesion into the damaged retina seemed to be also a secondary step after the proliferation. Phagocytic activities to engulf the retinal debris were observed in Müller's cells and the retinal pigment epithelial cells. Whether or not astrocytes in the retina do proliferate and are involved in the scar formation after the photocoagulation still remains unanswered. Electron microscopic autoradiography using tritiated thymidine after photocoagulation in the monkey retina might answer the question.