What Causes Macular Edema?

Macular edema is caused by pockets of fluid (usually leakage from damaged blood vessels) swelling up in the macula. 

There are many conditions that can leak fluid into the retina and cause macular edema, including:

• Diabetes. With diabetes, high blood sugar levels damage blood vessels, which leak into the macula.
• Age-related macular degeneration (AMD). With AMD, abnormal blood vessels leak fluid and cause macular swelling.
• Macular pucker/vitreomacular traction. When vitreous in the aging eye doesn’t detach completely from the macula, the vitreous tugs on the macula or forms scar tissue, and pockets of fluid collect underneath it.
• Retinal vein occlusion (RVO). With blood vessel diseases like RVO, veins in the retina become blocked. Blood and fluid then leak out into the macula.
• Hereditary/genetic disorders (passed from parent to child), such as retinoschisis or retinitis pigmentosa.
• Inflammatory eye diseases. Conditions like uveitis, where the body attacks its own tissues, can damage retinal blood vessels and cause swelling of the macula.
• Medication. Certain drugs have side effects that can lead to macular edema.
• Eye tumors. Both benign and malignant tumors can lead to macular edema.
• Injuries. Trauma to the eye.