The purpose of this study is to determine whether a fluocinolone sustained drug delivery implant is effective in the treatment of central retinal vein occlusion that has caused persistent macular edema and decreased visual acuity.

Currently there is limited treatment for macular edema and vision loss due to central retinal vein occlusion. Case reports have shown some benefit of intravitreal steroid injections in improving vision and reducing macular edema in eyes with retinal vein occlusions.

Recently, a sustained drug release steroid implant has been investigated and FDA approved to treat macular edema in patients with non-infectious uveitis, eye inflammation. This implant is placed through an incision in the eye wall and is designed to deliver a steroid, fluocinolone acetonide, for up to three years. In animal studies there was no detectable steroid seen in the blood stream.

This pilot trial will recruit individuals who have had a central retinal vein occlusion in at least one eye. If the macular edema and vision improves with an initial intravitreal injection, the eye will be considered to receive the sustained drug release device. The dosage of fluocinolone acetonide used is 0.59 mg.

Inclusion Criteria:

Patients are eligible to receive an implant if they met all the following criteria:

• A history of central retinal vein occlusion that had caused macular edema, based on clinical evaluation and demonstrated on fundus photography, fluorescein angiography, and optical coherence tomography (OCT)
• Macular edema at least one disc area in size that involved the fovea
• Males and non-pregnant females at least 18 years of age
• Intraocular Pressure (IOP) controlled at < 21 mmHg with no more than one topical ocular antihypertensive agent
• Ability and willingness to comply with treatment and follow up process and to understand and sign the informed consent form.
• Initially, patients with central retinal vein occlusion were not required to have previous therapy. However, the protocol was subsequently modified to require an intravitreal injection of triamcinolone acetonide > 12 weeks prior to study entry, with an initial decrease in macular edema and improvement in visual acuity and subsequent decline in visual acuity accompanied by increased macular edema. This modification was added to avoid enrolling patients who might have had a long-lasting response to a single intravitreal triamcinolone acetonide injection.

Exclusion Criteria:

• Patients are excluded if they have an allergy to fluocinolone acetonide or any component of the delivery system, a peripheral retinal detachment in the area of implantation, or media opacity precluding evaluation of study eye status.
• Patents with disciform scars of the fovea or atrophic changes of the macula that in the investigator's opinion would preclude benefit from treatment are excluded from the study.
• Female patients who were pregnant or lactating or not taking precautions to avoid pregnancy.

Twenty nine participants were consented. Of the 29 consented (30 eyes; one subject consented twice), 23 participants were studied and 24 eyes. Both eyes of one participant were studied

3 years