Argon laser photocoagulation of choroidal malignant melanomas from a 54-year-old man and a 46-year-old woman was carried out. The globes were enucleated 24 hours postcoagulation and studied histopathologically. Because the tumors studied were flat, heavily vascularized, and (in one of the cases) pigmented, they would theoretically appear to be candidates for destruction by argon therapy. Tumor cell necrosis was seen only in the superficial aspect of the masses after a single treatment, however, and extensive fragmentation and breakdown of tumor vessels with associated hemorrhage occurred. Such vessel damage is dangerous because an increased potential for vascular invasion (with subsequent tumor seeding or metastasis) is created.
Apple DJ, Goldberg MF, Wyhinny G. Argon Laser Photocoagulation of Choroidal Malignant MelanomaTissue Effects After a Single Treatment. Arch Ophthalmol. 1973;90(2):97-101. doi:10.1001/archopht.1973.01000050099004