Comparisons of photocoagulation treatment in exudative age-related macular degeneration with the blue-green argon, green argon and red krypton laser wavelengths.

Between November 1975 and December 1989, we examined 1,540 patients with age-related macular degeneration (ARMD). 297 eyes of 270 of these patients received photocoagulation treatment (from L.S.A.) for exudative ARMD, including choroidal neovascular membranes (CNVMs) and retinal pigment epithelial detachment. Initially, only the blue-green argon laser was available. From 1983 onwards we could choose between the blue-green argon, green argon and red krypton laser wavelengths. The 270 treated patients were followed for a minimum of 6 and a maximum of 168 months posttreatment (median 16 months). Of the 297 eyes, 138 received treatment with the blue-green argon, 36 with the green argon and 123 with the red krypton laser. Eyes with subfoveal and juxtafoveal NVMs were treated with the krypton laser. Also assigned to krypton photocoagulation were extrafoveal NVMs accompanied by hemorrhage. There was no statistical difference in the results of the three treatment modalities as judged by visual acuity. But, green argon is preferable to blue-green argon since it is absorbed less by the xantophyll pigment. On the other hand, krypton laser appears to be at least as effective as green argon in extrafoveal neovascularization and is certainly the treatment of choice in subfoveal and juxtafoveal NVMs.