 Patients who have ETDRS visual acuity of 2040 or worse, but better than or equal to 20320 due to foveal thickening from macular edema secondary to diabetes type 1 or 2 and who meet eligibility criteria will be eligible to enroll in the study. Baseline foveal thickness by OCT must be at least 250, which is often associated with VA of 2040 or worse and which provides sufficient thickening so that a treatment effect is easily detectable Nguyen et al. 2004. Approximately 126 patients with DME will be enrolled in this study from all clinical sites in the study. Every effort will be made to recruit and enroll eligible patients from men and women of all ethnic and social backgrounds. Patients who meet entry criteria will be able to enroll in the study until the quota of patients has been achieved. 