PROPHYLACTIC PERIFOVEAL LASER TREATMENT OF SOFT DRUSEN

Purpose: To assess the efficacy and safety of perifoveal laser to caus e drusen to resorb, and establish a treatment protocol. Methods: Treat ment technique was determined by the outcome in one patient with 15-ye ar follow-up. In an uncontrolled series a perifoveal ring of gentle la ser was applied to 30 eyes of 28 patients, 18 with bilateral drusen an d 10 with exudative disease in the fellow eye. Comparison was made bet ween treated and untreated eyes in 14 patients with bilateral drusen. Mean follow-up was 16.8 months (range, three to 42 months). Results: S oft drusen resorbed in all treated eyes in the vicinity of laser and w ithin the fovea. Large soft confluent drusen (>500 mu m) responded mos t rapidly. Visual acuity improved one or more lines in 12 (40%) treate d 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 re mained unchanged in 10 eyes and improved in four treated eyes while no ne of the untreated eyes improved (P = 0.03, chi(2)) and decreased in four eyes. Atrophic expansion of laser burns was minimal. CNV develope d in two of 30 eyes (7%). Conclusion: Perifoveal laser treatment appea rs to expedite the regression of soft drusen within the fovea. The ris ks of complications may be reduced by treating eyes early, before pigm ent changes develop and by applying a minimum number of burns at a dis tance greater than 750 mu m from the foveal centre. Treatment should c urrently 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.