Macular edema happens when fluid builds up in the macula, causing swelling. This can distort vision, making things look blurry and colors look washed out.
Without treatment, macular edema can even lead to permanent vision loss.
Cause
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.
- Eye surgery. It’s not common, but sometimes after glaucoma, retinal or cataract surgery, you can get macular edema.
- Injuries. Trauma to the eye.
Symptoms
Macular edema is painless and usually doesn’t have symptoms when you first get it. When you do have symptoms, they are a sign that the blood vessels in your eye may be leaking.
Common symptoms of macular edema include:
- blurred or wavy central vision
- colors appear washed out or different
- having difficulty reading
If you notice any macular edema symptoms, see an ophthalmologist as soon as possible. If left untreated, macular edema can cause severe vision loss and even blindness.
Diagnosis
During an eye exam, your ophthalmologist will dilate (widen) your pupils so they can look at your retina in the back of the eye.
Your ophthalmologist may do other tests that provide a more detailed look inside your eye, such as:
Optical Coherence Tomography (OCT). OCT is another way to look closely at the retina. A machine scans the retina and provides very detailed images of its thickness. This helps your doctor find leakage and measure swelling of the macula.
Fluorescein angiography. A yellow dye (called fluorescein) is injected into a vein, usually in your arm. The dye travels through your blood vessels. A special camera takes photos of the retina as the dye travels throughout its blood vessels. This shows whether any blood vessels are leaking and how much leakage there is.
Treatment
The best approach to treatment requires addressing the underlying cause of the macular edema, and the related leakage and retinal swelling.
Treatment for macular edema depends on what’s causing it, and can include:
Medication injections. There are medications called anti-VEGF drugs. Anti-VEGF treatment helps reduce abnormal blood vessels in your retina, and also decreases leaking from blood vessels. This medicine is delivered to your eye through a very slender needle.
Steroid treatment. When macular edema is caused by inflammation or leaking from blood vessels, steroid medication may be used. These drugs can be given by eye drops, pills, or injections.
Eye drop medication. To treat certain kinds of cystoid macular edema (or CME), your ophthalmologist may prescribe steroid eye drops, non-steroidal anti-inflammatory (NSAID) eye drops or dorzolamide drops for a few months.
Laser treatment. With this surgery, your ophthalmologist applies many tiny laser pulses to areas of fluid leakage around the macula. The goal is to stabilize vision by sealing off leaking blood vessels.
Vitrectomy surgery. When macular edema is caused by vitreous pulling on the macula, an in-office procedure called pneumatic vitreolysis, or operating room surgery called vitrectomy may be needed to restore the macula to its normal (lying flat) shape. During pneumaic vitreolysis a small gas bubble is injected into the eye to help separate the vitreous from the macula.
During vitrectomy, the surgeon uses tiny instruments to remove the vitreous from the eye and peel scar tissue from the macula. This relieves the traction that is damaging the macula.
Sometimes the swelling in your eye can cause you to have increased pressure within the eye, called glaucoma. In such cases, your ophthalmologist will treat you with medicines to control your glaucoma.
Depending on the cause of the macular edema and the treatment plan your doctor has recommended, the macular edema may take several months to resolve. During this time, it is important to follow the treatment regimen that your ophthalmologist recommends in order for your treatment to be effective.