Safety and Tolerability Study of the Helical Intravitreal Triamcinolone Implant in Diabetic Macular Edema

Inclusion Criteria: * Patients with clinically observable macular edema associated with diabetic retinopathy in study eye * Macular edema in study eye is associated with 1. visual acuity of 20/40 or worse; and 2. retinal thickening in the fovea as seen on biomicroscopic examination 3. angiographic evidence of leakage involving the perifoveal capillary net * Failure of macular edema to improve with prior macular photocoagulation, or the patient is unlikely to benefit from macular photocoagulation in the opinion of the investigator * Patients must be 18 years of age and older * Patients must be willing and able to return for scheduled follow up examinations for 3 years after initial surgery. * Patients must sign and be given a copy of the written Informed Consent form. Exclusion Criteria: * Monocular, or vision worse than 20/400 in the fellow eye * Visual acuity worse than 20/200 20/200 and \< 34 letters read in the study eye * Use of depot periocular steroids in the study eye within the past 30 days * Current use of \>15 mg/day of oral steroids * Known steroid responder * Ocular hypertension \> 22 mmHg in the study eye or need for more than one medication to maintain IOP \< 22 mmHg. * Cup to disc ratio of \> 0.8 in the study eye * Prior filtration surgery or glaucoma implant surgery in the study eye * Any active ocular infection in either eye * History of herpetic ocular infection in the study eye * Macular ischemia, defined as angiographic evidence of enlargement of the foveal avascular zone to 1 disc area or larger, centered on the fovea * Macular or panretinal photocoagulation treatment in the study eye within the past 90 days; laser capsulotomy within the past 90 days * Planned or known need for ocular surgery in the study eye within 90 days after enrollment and treatment * Any condition that precludes the subject's ability to comply with study requirements, including examinations or the completion of the study; or any condition that precludes the examiner's ability to obtain reliable fundus photography, angiography, or OCT images * Females who are pregnant or lactating, and premenopausal females who are unwilling to use a medically accepted method of birth control for the duration of the study * Participation in another investigational trial within 30 days prior to enrollment or during the study period * Uncontrolled hypertension (systolic BP \> 160 mm Hg and/or diastolic BP \> 90 mmHg) * Uncontrolled diabetes (HbA1c \> 13) * Chronic renal failure requiring dialysis or anticipated renal transplant * Retinal or choroidal neovascularization in the study eye; anticipated need for panretinal photocoagulation within the next 30 days * Macular edema in the study eye known to be due to a cause other than diabetic retinopathy * Use of immunosuppressant drugs