What is the Origin of Cystoid Macular Edema?

The term is derived from the Greek words kystis (bladder or sac), macula (spot), and oid (like), precisely describing the appearance of the fluid-filled sacs in the central retinal region. Edema comes from the Greek oidēma (swelling). This descriptive nomenclature has been utilized in ophthalmology for decades to categorize this specific, clinically recognizable pattern of retinal swelling.

What is the Mechanism of Cystoid Macular Edema?

CME results from the breakdown of the blood-retinal barrier, a specialized vascular structure that normally prevents fluid and plasma components from entering the neural retina. Inflammation, often secondary to cataract surgery, diabetic retinopathy, or vascular occlusion, increases the permeability of the perifoveal capillaries. The resulting fluid leakage overwhelms the retinal pigment epithelium's ability to pump fluid out, leading to its characteristic accumulation within the outer plexiform and inner nuclear layers of the macula.

Cystoid Macular Edema ∞ Area

Cystoid Macular Edema

Meaning

Cystoid Macular Edema (CME) is an ophthalmological condition characterized by the pathological accumulation of fluid within the macula, the central part of the retina responsible for sharp, detailed central vision. This excess fluid gathers in distinct, cyst-like pockets, causing significant swelling and distortion of the delicate retinal architecture. The resulting edema impairs the function of the macula’s photoreceptor cells, directly leading to a measurable decrease in visual acuity.