Proton therapy for exudative age-related macular degeneration: a randomized, sham-controlled clinical trial.

PURPOSE: To examine the effect of proton beam irradiation on subfoveal choroidal neovascular membranes (CNVM) associated with age-related macular degeneration (AMD).Randomized, prospective, sham-controlled, double-masked treatment trial.

METHODS: Thirty-seven subjects with subfoveal CNVM due to AMD were randomly assigned to 16-Gy proton irradiation delivered in two fractions 24 hours apart or to sham control treatment. Recruitment was halted at 37 subjects for ethical reasons regarding randomization to sham treatment when Food and Drug Administration approval of Visudyne was anticipated.

RESULTS: Proton irradiation was associated with a trend toward stabilization of visual acuity, but this association did not reach statistical significance. No correlations were found within the fluorescein angiography data, including greatest linear dimension of CNVM total size, area of active leakage, area of associated subretinal hemorrhage, and intensity.

CONCLUSIONS: With the acceptance of photodynamic therapy, future studies will require more complex design and larger sample size to determine whether radiation can play either a primary or adjunctive role in treating these lesions.