Macular edema is the accumulation of fluid in an area in the center of the retina (the macula) that causes the macula to swell and thicken, which distorts vision. The macula is a part of the retina and is responsible for sharp, straight-ahead vision.
Diabetic macular edema is a complication of diabetes and is the most frequent cause of vision loss related to diabetes.
Treatment for diabetic macular edema first aims to address the diabetes. After diabetes is managed, treatment is often the same for diabetic macular edema and macular edema caused by other conditions.
In addition to controlling diabetes, treatments for diabetic macular edema include:
- Anti-VEGF injections
- Numbing drops are applied to the eye
- A short thin needle injects medication into the fluid in the center of the eye (vitreous gel)
- Drugs used in this treatment include bevacizumab (Avastin), aflibercept (Eylea), and ranibizumab (Lucentis)
- These drugs work to block vessel formation and prevent leakage in the retina
- Anti-inflammatory treatments
- Corticosteroid treatments to reduce inflammation
- Administered via eye drops, pills, or injections of sustained-release corticosteroids into or around the eye
- Corticosteroid implants may be used for more serious or longer-lasting conditions:
- Dexamethasone (Ozurdex)
- Fluocinolone acetonide (Retisert, Iluvien)
- Nonsteroidal anti-inflammatory drugs (NSAIDs)
- Administered as eye drops
- May be used when the eye doesn’t respond to steroids or to avoid the side effects of steroid use in the eye
- Corticosteroid treatments to reduce inflammation
- Vitrectomy
- Surgery to remove the vitreous gel (the gel that fills the area between the lens and the retina) may be needed to relieve pulling on the macula, or to remove blood that has collected in the vitreous, or to correct vision if other treatments do not work
- Laser treatments
- Laser photocoagulation (an older treatment)
- Subthreshold diode-laser micropulse technology and selective retina therapy (SRT) (still being studied)
What Are Symptoms of Diabetic Macular Edema?
Symptoms of diabetic macular edema include:
- Blurred or wavy vision near or in the center of the field of vision
- Symptoms can range from slightly blurred vision to noticeable vision loss
- Colors may appear washed out or faded
- “Floaters”
- Double vision
What Causes Diabetic Macular Edema?
- Diabetic macular edema is caused by a complication of diabetes called diabetic retinopathy, which is a result of continuing damage to the small blood vessels of the retina. Leakage of fluid into the retina can lead to swelling of the surrounding tissue, including the macula.
- Poor blood sugar control and other underlying medical conditions, such as high blood pressure (hypertension), increase the risk of blindness in people who have diabetic macular edema.
How Is Diabetic Macular Edema Diagnosed?
Macular edema, including diabetic macular edema, is diagnosed with a physical examination of the eye to look for abnormalities in the retina.
Tests used to determine the location and extent of the disease may include:
- Visual acuity test
- Used to identify vision loss
- Uses a standardized chart or card with rows of letters that decrease in size from top to bottom
- The patient covers one eye and is asked to read out loud the smallest line of letters they can see
- Dilated eye exam
- Used to thoroughly examine the retina
- Can detect the presence of blood vessel leakage or cysts
- Drops are placed in the eyes to dilate the pupils and a doctor examines the retina
- Fluorescein angiogram
- A special dye is injected into an arm and a camera takes photos of the retina as the dye travels through the blood vessels
- This can help identify the extent of damage to the macula
- Optical coherence tomography
- Uses a special light and a camera for detailed views of the cell layers inside the retina
- Detects the thickness of the retina and the amount of swelling in the macula
- May also be used to track how well a patient is healing
- Uses a special light and a camera for detailed views of the cell layers inside the retina
- The Amsler Grid
- This can be done at home
- The grid consists of a chart with lines and a dot in the center
- The patient looks at the chart with one eye closed and then the other
- Lines may appear wavy instead of straight in patients who have macular edema
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Reviewed on 10/28/2021
References
Image Source: iStock Images
https://www.nei.nih.gov/learn-about-eye-health/eye-conditions-and-diseases/macular-edema
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3277023/
https://www.nei.nih.gov/learn-about-eye-health/eye-conditions-and-diseases/macular-edema
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3277023/