Macular edema is a complication associated with diabetic retinopathy, as well as wet cases of age-related macular degeneration, uveitis, branch retinal vein occlusion (BRVO), and central retinal vein occlusion (CRVO). Macular edema is a swelling of the macula – the central part of the retina responsible for clear, detailed vision – caused by damaged blood vessels leaking into the retina. As these fluids accumulate in the macula, it obscures light from passing through and results in a loss of central vision. In severe cases, macular edema can result in blindness.
Given the range of underlying conditions that may cause macular edema, the severity of vision loss and necessary treatment will vary from patient to patient.
Symptoms of Macular Edema
At early stages, noticeable symptoms of macular edema may not be apparent. Yet, as fluids continue leaking into the retina, vision will gradually become distorted.
Symptoms of macular edema include:
- Blurred or distorted vision, straight lines may appear wavy.
- Difficulty seeing details or reading fine print
- Double vision
- The appearance of floaters – small dark shapes that resemble cobwebs or pieces of dust – in the frontal field of vision.
Regular eye exams can identify this condition before vision loss begins to occur and increases the likelihood of successful treatment. Anyone diagnosed with diabetes should schedule an eye exam at least once a year.
Patients are strongly recommended to notify their retina specialist immediately if they notice any changes in their vision.
Causes of Macular Edema
Anyone suffering from diabetes is at a significantly greater risk of developing macular edema due to complications caused by diabetic retinopathy. This is one of the leading causes of blindness amongst Canadians.
Macular edema can also be caused by other retinal conditions including branch retinal vein occlusion, central retinal vein occlusion and the wet form of age-related macular degeneration.
The severity of macular edema and degree of vision loss is increased if diabetes and high blood pressure are not being properly managed.
Diagnosing Macular Edema
Your retinal specialist can detect macular edema, even in early stages, during a comprehensive dilated eye exam. Your retinal specialist will also be looking for the presence of abnormal blood vessels leaking fluids into the retina.
Once diagnosed with macular edema, your retinal specialist may require additional diagnostic testing to assess the severity of the case. Patients are most likely to undergo an optical coherence tomography (OCT) and fluorescein angiogram examination. The fluorescein angiogram is used to identify abnormal blood vessels and whether these are leaking into the retina while an OCT examination will be used to assess the swelling of the macula.
Further rounds of diagnostic testing may be scheduled during treatment to determine if swelling and leaking from blood vessels are being controlled effectively.
Treatment of Macular Edema
The necessary treatment for macular edema varies for each patient depending on the severity of vision loss, underlying retinal conditions, and how early this condition has ben identified.
Brief summaries of the treatments for macular edema are outlined below. Patients that have been diagnosed with diabetic retinopathy will notice that there is overlap in treatments. Please click upon the name of the treatment to be redirected to a page with a more detailed description.
Focal Macular Laser Treatment: This laser treatment is used to control bleeding and leakage caused by abnormal blood vessels. During laser treatment, a series of small, painless burns are made to the abnormal blood vessels. This seals the leaks and prevents further bleeding into the retinal.
Avastin or Lucentis Injections: Avastin and Lucentis are both anti-VEGF medications that are injected into the eye. These medications block the chemical responsible for the leakage. Avastin and Lucentis help mitigate the vision loss caused by fluids leaking from these blood vessels.
Periocular and Intravitreal Steroid Injections: Periocular and intravitreal injections of corticosteroids, such as Kenalog, can be used to manage macular edema in conjunction with laser treatment. Regular injections of steroids help to reduce swelling of the macula and leakage of abnormal blood vessels.