IDO1 and macular retinal edema: Using flow cytometry, we evaluated monocyte and IDO-expressing monocyte-like myeloid-derived suppressor cell (MDSC) subpopulations in PB samples from 15 patients with different courses of PP (cystoid macular edema and non-macular edema subgroups; CME and nCME, respectively) and 17 healthy controls (HCs) in relation to the Th1, Th17, and immunoregulatory subsets.