Subretinal new vessel recurrence in age-related macular degeneration.

Laser photocoagulation with argon or krypton is currently used to treat selected patients with age-related macular degeneration and sudden visual loss from subretinal new vessel formation. In 102 consecutive cases, treated over two years, closure of the vessels was achieved without additional major visual loss in 79% when assessed at two months. Early failure occurred in 21% and was due either to selection of cases with central location or failure to close the new vessel. Later failures due to recurrent subretinal new vessel formation or progression of other macular degenerative changes has occurred in a further 28% so far. Although controlled clinical trials show a significant benefit of treatment, the overall impact of these few successes on the population with macular degeneration is small. Further understanding of the mechanism of subretinal new vessel formation is urgently required. Areas under investigation include the response of injured retinal pigment epithelium, choroid and retina and cellular production of facilitatory factors including proteases and fibronectin.