Prophylactic perifoveal laser treatment of soft drusen.
PURPOSE: To assess the efficacy and safety of perifoveal laser to cause drusen to resorb, and establish a treatment protocol. METHODS: Treatment technique was determined by the outcome in one patient with 15-year follow-up. In an uncontrolled series a perifoveal ring of gentle laser was applied to 30 eyes of 28 patients, 18 with bilateral drusen and 10 with exudative disease in the fellow eye. Comparison was made between treated and untreated eyes in 14 patients with bilateral drusen. Mean follow-up was 16.8 months (range, three to 42 months). RESULTS: Soft drusen resorbed in all treated eyes in the vicinity of laser and within the fovea. Large soft confluent drusen (> 500 microns) responded most rapidly. Visual acuity improved one or more lines in 12 (40%) treated eyes, was unchanged in 16 (53%) and deteriorated in two (7%). In 14 patients with bilateral drusen in whom only one eye was treated, VA remained unchanged in 10 eyes and improved in four treated eyes while none of the untreated eyes improved (P = 0.03, chi 2) and decreased in four eyes. Atrophic expansion of laser burns was minimal. CNV developed in two of 30 eyes (7%). CONCLUSION: Perifoveal laser treatment appears to expedite the regression of soft drusen within the fovea. The risks of complications may be reduced by treating eyes early, before pigment changes develop and by applying a minimum number of burns at a distance greater than 750 microns from the foveal centre. Treatment should currently be administered only in the context of a prospective clinical trial, which is required to assess whether this treatment results in lowered risk of visual loss from CNV or geographic atrophy.