[Dye laser photocoagulation treatment for experimental subretinal neovascularization. 1. Histopathological findings of healing process].

To clarify the healing process of subretinal neovascularization (SRN) histopathologically following laser photocoagulation treatment, we performed laser photocoagulation for experimental SRNs produced in rhesus monkey eyes. To produce long-lasting SRNs, 0.5M 1-ornithine hydrochloride solution was injected intravitreously 2 weeks after photocoagulation. These SRNs were treated a 590nm dye laser, and examined clinically and histopathologically at 24 hours, 2 weeks, 3 months. Histopathologically, new vessels in the subretinal space were coagulated intensely and disappeared during the course of healed lesion. In these lesions, the retinal pigment epithelial cells proliferated in the subretinal space after the disappearance of the SRNs and covered the scar tissue. In strongly coagulated lesions, glial cells were related to the formation of scar tissue. These results showed that closure of new vessels was necessary for the healing of SRNs by photocoagulation and proliferation of the retinal pigment epithelial cells and glial cells occurred during their healing process.