Cystoid macular edema. A, Fluorescein angiogram demonstrates late pooling of dye in a petaloid pattern in the macula and staining of the optic disc. B, Spectral domain optical coherence tomography (SD-OCT) scan shows diffuse retinal thickening with cystic areas of low reflectivity predominantly in the inner nuclear and outer plexiform layers. A nonreflective cavity beneath the neurosensory retina can also be seen.