A Phase I Study of Episcleral Dexamethasone for Treatment of Macular Edema

Inclusion Criteria: * Type I or II diabetes; * Age \>= 18 years; * Visual acuity letter score in study eye \< 70 and ≥ 25 letters (approximate Snellen equivalent 20/32 to 20/320); * Ophthalmoscopic evidence of center-involved DME, within the central subfield (CSF); * OCT CSF thickness value (microns): * Zeiss Cirrus: ≥290 in women; ≥305 in men * Heidelberg Spectralis: ≥305 in women; ≥320 in men * Previous treatment with laser, anti-VEGF therapy and/or intravitreal steroids; * No previous history of glaucoma or steroid-induced intraocular pressure response in either eye. Exclusion Criteria: * History of chronic renal failure requiring dialysis or kidney transplant; * Retinal or optic nerve neovascularization on clinical exam, fundus photographs, or fluorescein angiograms; * Evidence of external ocular infection; * History of open-angle glaucoma or intraocular pressure \>= 25 mmHg; * History of steroid-induced IOP elevation that required IOP-lowering treatment; * History of prior herpetic ocular infection; * History of intravitreal or periocular corticosteroids within 3 months prior to enrollment; * History of macular laser photocoagulation within 4 months prior to enrollment; * History of antiangiogenic therapy within 4 weeks prior to enrollment; * History of panretinal photocoagulation (PRP) within 4 months prior to enrollment or anticipated need for PRP in the next 6 months following enrollment; * Presence of vitreomacular traction, epiretinal membrane, tractional retinal detachment, vitreous hemorrhage and or any ocular condition that the investigator judges could interfere in the safety and efficacy assessments; * No other major non-diabetic pathology, or anticipation of such in the next 6 months following enrollment that in the opinion of the investigator would substantially and adversely affect assessment of safety and toxicity during the study; * Participation in another clinical trial of non-approved medical treatment within 3 months prior to enrollment; * Degenerative myopia; * Malignant intraocular disease; * Inability to understand informed consent, cooperate with testing or return to follow up visits; Pregnant or lactating women; Co-existent ocular disorder of the cornea, lens or media that will interfere with assessment of safety or efficacy.