Macular thickening Retinal edema Macular edema SNOMEDCT_US:37231002 UMLS:C0271051 Thickening of the retina that takes place due to accumulation of fluid in the macula as a nonspecific response to blood-retinal barrier breakdown. Macular edema is a common pathological response to a wide variety of ocular insults, most commonly after intraocular (e.g. cataract) surgery or in association with retinal vascular (e.g. diabetic eye disease, retinal vein occlusion) or inflammatory (e.g. uveitis) disease. edematous macula lutea