• Adults between the ages of 18 and 85 Willingness to participate in the study and provide informed consent For Phase A, patients who only respond to anti-inflammatory drops (not at the intravitreal steroid injection phase of care yet).

• For Phase B, patients who only respond to steroid intravitreal injections (anti-inflammatory drops are no longer therapeutically working for these patients).

• Corneal thickness between 480 and 620 µm in the study eye by anterior segment OCT.

• Diagnosis of cystoid macular edema in the study eye defined as macular edema involving the center of the macula (fovea) with one or more of the following OCT characteristics: retinal cysts, retinal thickening, and/ or subretinal fluid.

• Visual acuity between 20/400 and 20/25 in the study eye, measured by pinhole VA.

• Retinal thickness above 300 µm as measured by OCT in the 1mm central macular subfield of the study eye at screening as determined by the investigator History of positive response to topical or intraocular steroid treatment defined as 50 µm thinning in response to steroid treatment in the study eye within 1 year Recurrence of cystoid macular edema in the study eye

• Patients who have received intravitreal triamcinolone acetonide in the study eye must satisfy the following:

• The most recent dose was at least 8 weeks prior to screening No treatment-related adverse event was seen that, in the opinion of the investigator, has the potential to worsen or reoccur with study treatment.

• Female patients of childbearing potential must have a negative urine pregnancy test at the enrollment (day 0) visit (repeat at day 0 if greater than 14 days past Screening Visit) Aphakia or pseudophakia in the study eye