Results from the Diabetic Retinopathy Study (DRS) demonstrate that scatter photocoagulation is associated with some loss of visual acuity soon after treatment. This visual loss is especially prominent in eyes with preexisting macular edema. It is also associated with the intensity of treatment. Reducing macular edema by focal photocoagulation before initiating scatter treatment and dividing scatter treatment into multiple sessions with less intense burns may decrease the risk of the visual loss associated with photocoagulation.