[The process of occlusion and re-construction of the choriocapillaries following dye laser photocoagulation].

In order to elucidate the histopathological changes in the choriocapillaries following laser photocoagulation, moderate laser burns were performed on monkey retinas by an orange dye laser beam (595nm). Immediately after photocoagulation, the choriocapillaries were occluded by the intraluminal thrombus, however, the basement membrane of the endothelial cells remained. The newly-formed immature endothelial cells began to migrate along the pre-existing basement membrane toward the center from the edge of the lesion after 3 days. They formed new vascular lumens by coupling of intercellular junctions at 5 days. At 7 days, newly-formed capillaries were formed beneath the Bruch's membrane. After more than 7 days, the choriocapillaries in the lesion were re-constructed and required an almost normal structure with wide patent lumens, basement membrane, pericytes and fenestrations. It was showed that choriocapillaries occluded by moderate laser photocoagulation were re-constructed by the process of re-endothelialization along the preexisting basement membrane.