For patients with two study eyes (both eyes eligible at the time of randomization), the right eye (stratified by visual acuity and prior laser) will be randomly assigned with equal probabilities to one of the three treatment groups listed above. The left eye will be assigned to the alternative treatment (laser or triamcinolone). If the left eye is assigned to triamcinolone, then the dose (1mg or 4 mg) will be randomly assigned to the left eye with equal probability (stratified by visual acuity and prior laser).