Macular edema is the term used for swelling or fluid in the macula (central portion of the retina). The swelling causes decreased visual function. There are many causes of macular edema. Some macular edema occurs after eye surgery or trauma, giving the appearance of cysts in the retina (cystoid macular edema). Other macular edema is caused by damage to the small blood vessels of the retina from diabetic retinopathy. Macular edema is also part of the spectrum of wet macular degeneration, where fluid as well as blood leaks out of abnormal blood vessels.
Other causes of macular edema include radiation exposure, macular pucker, nicotinic acid, vitreomacular traction, prostaglandin containing eye drops for glaucoma (Travatan Z, Lumigan, Xalatan), uveitis, retinitis pigmentosa, and retinal vein occlusions (BRVO / CRVO).
The treatment of macular edema varies depending on its cause. A course of prescription eye drops may suffice, but a peri-ocular (around the eye) injection or intraocular (within the eye) injection of steroids or anti-VEGF agents is needed. Occasionally laser treatment or surgery may be necessary as well.