Argon green vs krypton red laser photocoagulation of extrafoveal choroidal neovascular lesions. One-year results in age-related macular degeneration. The Canadian Ophthalmology Study Group.

This multicenter randomized controlled clinical trial performed in Canada was designed to determine whether krypton red laser or argon green laser is superior for treatment of choroidal neovascularization located between 200 and 2500 microns from the center of the foveal avascular zone in patients with age-related macular degeneration. Two hundred ten patients were randomly assigned to treatment with either argon green or krypton red laser, of whom 191 (91%) were determined eligible. Of the eligible patients, 185 (97%) had sufficient follow-up for a comparison of primary-outcome visual acuity at 1 year. We conclude, with 95% confidence, that the krypton red laser is no better than the argon green laser for the treatment of well-defined extrafoveal choroidal neovascularization.