This is called cystoid macular edema (CME) There are a few possible late-onset complications of cataract surgery that can affect the vision four to six months after the surgery. This condition occurs in susceptible patients even after uncomplicated cataract surgery. The central portion of the retina responsible for our sharpest vision, the macula, develops some fluid-filled (edema) cysts. Cystoid macular edema or CME, is a painless disorder which affects the central retina or macula. When this condition is present, multiple cyst-like (cystoid) areas of fluid appear in the macula and cause retinal swelling or edema.