Macular edema is a condition in which fluid builds up in the macula causing it to swell and thicken, distorting vision. Macular edema cannot be cured but can be treated effectively if diagnosed early.
Macular edema cannot be cured but can be treated effectively if diagnosed early. Vision can be better preserved with early treatment of macular edema and the underlying condition causing it. Recovery from macular edema is slow and gradual and may even take months.
The degree of visual recovery depends on the successful management of the underlying condition and the severity of retinal damage. Maintaining a healthy weight, keeping diabetes, blood pressure, and cholesterol levels under control can help prevent worsening of macular edema.
What is macular edema?
Macular edema is a condition in which fluid builds up in the macula causing it to swell and thicken, distorting vision. The macula is the central part of the retina, the light-sensitive layer of tissue at the back of the eye. The macula is in the center of the retina, about 5 mm across, with a high concentration of photoreceptor cells.
The macular region is responsible for central vision, fine details, and colors, while the rest of the retina processes peripheral vision. The retina detects light and converts it into electrical impulses that are transmitted by the optic nerve to the visual cortex of the brain, which processes them, resulting in vision.
What are the symptoms of macular edema?
Macular edema is painless and initial symptoms may not be noticeable, especially if only one eye is affected. The symptoms of macular edema include the following:
- Blurry central vision
- Distorted central vision, for example, straight lines appear wavy
- Washed out or faded colors
- Vision loss in advanced stages
What causes macular edema?
Macular edema is caused by leakage and accumulation of fluid in the macula when tiny blood vessels (capillaries) in the retina get damaged. The fluid collects in tiny sacs known as cysts, which obscure the central vision. Macular edema is not a disease by itself but is a symptom of an underlying condition.
Macular edema can occur from the following conditions:
- Diabetes: Diabetic retinopathy is a condition in which retinal blood vessels are damaged due to high blood sugar.
- Age-related macular degeneration (AMD): AMD is the degeneration of the macula that occurs with age. In wet AMD, abnormal blood vessels form and leak fluid into the macula.
- Eye surgery: Eye surgeries for cataracts or glaucoma can cause temporary damage to retinal blood vessels.
- Vascular diseases: Diseases such as high blood pressure or atherosclerosis can cause blood vessel blockages, leading to fluid leaks.
- Inflammatory diseases: Inflammatory diseases such as uveitis that affect the eye can damage the retinal tissue. The retina can also be affected by inflammatory immune system disorders such as:
- Genetic eye disorders: Inherited genetic eye conditions such as:
- Retinitis pigmentosa, a condition in which retinal cells break down
- Retinoschisis, a condition in which retinal layers split abnormally
- Other conditions: Other conditions that can damage the macula include:
- Eye tumors
- Eye injury
- Certain medication side effects
What is the best treatment for macular edema?
Treatment for macular edema depends on the condition that caused it. You may be required to undergo eye tests such as:
- Visual acuity test: Test with a chart of alphabets or numbers.
- Amsler grid: A simple test with a grid and a dot to focus on, one eye at a time, which can detect wavy central vision.
- Dilated eye exam: A physical exam in which the doctor uses eye drops and dilates the pupil to better examine the eye.
- Fluorescein angiogram: A test in which the doctor injects into the arm a dye that travels into the eye’s capillaries. The dye leaking through damaged blood vessels is captured in pictures with a special camera, which can show the extent and exact spot of leakage.
- Optical coherence tomography (OCT): Use of a device with a camera and light that enables the doctor to get a detailed view of the retina.
Treatment for macular edema includes treating the underlying condition. Common treatments for damage to the retina from macular edema include:
- Eye drops: Non-steroidal anti-inflammatory drug (NSAID) eye drops to control inflammation in cystoid macular edema which can occur after cataract surgery.
- Corticosteroids: Corticosteroids are the main treatment for macular edema from inflammatory diseases. Corticosteroids may be administered as oral pills or injections into the eye. Macular edema from chronic conditions is treated with retinal implants which slowly release the medication. FDA has approved the following corticosteroid implants:
- Anti-VEGF injections: Anti-VEGF is a medication that blocks the activity of a protein known as vascular endothelial growth factor (VEGF) that is essential for new blood vessel growth (angiogenesis). Anti-VEGF medications injected into the eye prevent abnormal blood vessel formation and leakage into the retina. Anti-VEGF drugs include:
- Bevacizumab (Avastin)
- Ranibizumab (Lucentis)
- Aflibercept (Eylea)
- Pegaptanib (Macugen)
- Laser treatment: Use of laser beam to seal leaking blood vessels in a process known as laser photocoagulation.
- Vitrectomy: Vitrectomy is a surgical procedure in which the doctor removes the vitreous, gel-like fluid that fills the space inside the eye between the lens and the retina. Vitrectomy is done when blood leaks into the vitreous clouding the vision, and the vitreous is replaced with clear fluid.
Does macular edema go away by itself?
Macular edema does not often cause permanent vision loss, but rarely goes away on its own. You must see an ophthalmologist immediately if you notice symptoms of macular edema. Untreated, macular edema can sometimes lead to complete vision loss.