• Adults with type 1 or 2 diabetes mellitus

• At least one eye with:

‣ Best corrected E-ETDRS visual acuity letter score ≥ 74 (i.e., 20/32 or better)

⁃ Ophthalmoscopic evidence of center-involved DME in study eye confirmed by central subfield thickness on spectral domain OCT

⁃ Zeiss Cirrus: ≥ 290 µm in females, ≥ 305 µm in males

⁃ Heidelberg Spectralis: ≥ 305 µm in females, ≥ 320 µm in males

∙ Recruitment will be monitored with a goal to have equal proportions in the following categories above the CI-DME thresholds: \<75 μm, 75 μm to \<175 μm, ≥175 μm

• Media clarity, pupillary dilation, and study participant cooperation sufficient for adequate OCT