Macugen for Proliferative Diabetic Retinopathy Study With Extended Dosing (M-PDRS ED)

Primary Objective: To further establish the efficacy of intravitreal pegaptanib injections in the regression of retinal neovascularization secondary to high-risk PDR, as compared to standard panretinal photocoagulation (PRP) Secondary Objective: To maintain the regression of PDR after the induction phase with intravitreal pegaptanib injections administered at 12-week intervals, as compared to standard PRP To maintain the regression of PDR after the induction phase with retinal photocoagulation applied to areas of ischemia (Selective Laser Photocoagulation), as compared to standard PRP To evaluate the rate of recurrence of neovascularization after 6 intravitreal pegaptanib injections To determine if intravitreal pegaptanib will reduce the area and/or volume of concomitant diabetic macular edema, as assessed by leakage on fluorescein angiography (FA) and/or optical coherence tomography (OCT) To determine if intravitreal pegaptanib injections maintain or reduce the loss of best-corrected visual acuity