This Phase 1 study will evaluate the safety, tolerability and duration of effect of a helical intravitreal triamcinolone implant for the treatment of diabetic macular edema over a three-year period.

The Helical Intravitreal Triamcinolone Implant is intended to provide sustained release of triamcinolone acetonide into the vitreous chamber of the eye.

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