Dr. Shashank Rai Gupta
Macular edema occurs when the retina’s ability to absorb fluid is overwhelmed by the fluid leaking into it. If more rain falls on the lawn than it can handle, you get puddles of water. In the retina, blisters of fluid form and swell the retina—this is macular edema. Factors likely to cause macular edema include conditions that:
- Cause more fluid to leak from blood vessels (diabetes and high blood pressure)
- Increase inflammation in the eye (surgery, inflammatory diseases)
- Are associated with the growth of abnormal blood vessels (wet age-related macular degeneration)
Macular edema refers to an abnormal blister of fluid in the layers of the macula.The swollen retina distorts images—making it more difficult to see clearly. The more widespread, thicker, and severe the swelling becomes, the more likely one will notice visual symptoms of blur, distortion, and difficulty reading.
If untreated, chronic macular edema can lead to irreversible damage of the macula and permanent vision loss. Macular edema is typically caused by increased leakage from damaged retinal blood vessels or growth of abnormal blood vessels in the deep retina. New vessels (neovascularization or NV) do not have normal “tight junctions” and almost always result in abnormal leakage of fluid (serum from the bloodstream) into the retina.
Macular edema is not a disease, but is the result of one.
Macular edema can be caused by many factors including
- Metabolic conditions (diabetes)
- Blood vessel diseases (vein occlusion/blockage)
- Aging (macular degeneration)
- Hereditary diseases (retinitis pigmentosa)
- Traction on the macula (macular hole, macular pucker, and vitreomacular traction)
- Inflammatory conditions (
- conditions (eye tumors)
- Surgical causes (following eye surgery)
- Unknown causes
Fluorescein angiography and optical coherence tomography (OCT; Figure ) are 2 common tests to evaluate macular edema. Based on the appearance of fluid on these tests, macular edema may be widespread, localized, or be made up of many small blisters surrounding the center of the macula—a common form called cystoid macular edema.
Treatment and prognosis
The most effective treatment strategies for macular edema address the underlying cause (diabetes, blood vessel occlusion, neovascularization, inflammation, etc), as well as an excess of fluid leaking from abnormal blood vessels in and around the macula.
Eye drops,medication, laser, and surgery can be effective in many diseases, but the mainstay of treatment is intravitreal injections (IVI). If macular edema is localized then Focal laser can be done.
The IVI is an day care procedure performed under topical anesthesia in which medication is placed inside the eye by a very small needle. The injection genrally causes little to no pain. IVI should be performed by a trained retina specialist with meticulous monitoring of treatment efficacy and detection of rare but potentially serious complications. IVI is now considered one of the most commonly performed medical procedures.
Is Founder Chairman of Delhi Eye Care. He is specialist in Vitreo-Retina, Uveitis & Diabetic Eye Care. He is visiting consultant at Sunetra Eye & Laser Centre, Ghaziabad, Narang Eye Institute, Model Town, New Delhi, Dr. Aggarwal’s Clinic, New Delhi and Apollo Spectra, Karol Bagh.