Retinal Conditions
Neovascular (Wet) AMD
Age-Related Macular Degeneration (AMD) is a condition that affects the central retina (macula), which is most important for reading vision and daily tasks. Neovascular (also called “wet” because of the presence of abnormal fluid or blood) AMD is an advanced form of the disease and can cause rapid and severe loss of central vision in one or both eyes. A diagnosis of wet AMD used to mean unavoidable loss of vision, but current treatments allow retina specialists to control the disease in the vast majority of cases.
What Causes Wet AMD?
The onset of age-related macular degeneration is determined largely by genetics, environmental factors and age. Only a small fraction of individuals with AMD go on to develop the advanced wet form, and this progression cannot currently be accurately predicted by genetics. Smoking greatly increases the risk of developing wet AMD.
In the wet form of AMD, abnormal blood vessels grow under the retina. These blood vessels can leak or break, resulting in blood or fluid collections. If this occurs behind the central retina, vision can drop dramatically. If treatment is delayed, blood or fluid can be toxic to the retina, resulting in permanent damage which cannot be fully treated.
How is Wet AMD Diagnosed?
Because several different diseases can produce blood or fluid in the central retina, your retina specialist will usually order tests to confirm the diagnosis of wet AMD and also document a starting point for treatment in order to measure progress over time.
Optical coherence tomography (OCT) is a fast, non-invasive scan of the retina which measures and locates fluid in and behind the retina. Fundus photography is the use of high resolution photographs to document the tissue appearance. Fluorescein angiography (FA) identifies the source of leakage of fluid under and within the retina with a series of timed photographs taken after intravenous injection of fluorescein dye.
Your BARA doctor will use these diagnostic tests to monitor the response of disease to treatment over time. OCT is used to monitor changes most frequently, while the other tests are repeated less often.
Treatment of Wet AMD
The primary treatment for wet AMD is injection of medication into the back part of the eye, known as the vitreous. The leakage of blood and fluid in wet AMD is caused by a hormone called VEGF (vascular endothelial growth factor). The medicines injected into the eye block this hormone (anti-VEGF medicines). There are several medicines currently used as treatment for wet AMD:
Anti-VEGF injections
The mainstay of treatment for wet AMD is the injection of anti-VEGF injections into the eye (see separate handout on injections). Anti-VEGF medications are non-steroid medications that suppress leakage or proliferation by damaged blood vessels. Anti-VEGF injections usually have to be repeated regularly in order to control the edema. Your BARA physician will talk to you about frequency of treatment and choice of medication in your particular case. There are several anti-VEGF medications currently used to treat wet AMD :
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Bevacizumab (Avastin) has been used off-label in the eye for more than 15 years
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Aflibercept 2mg works slightly differently than bevacizumab and in many cases is more effective. Aflibercept 2mg was first approved under the brand name Eylea and now has numerous approved biosimilar versions (the term ”generic” does not apply to this type of complex medication but the concept is the same) which the FDA considers equivalent (equally effective and safe) and which can used at the same dosing intervals.
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Faricimab (Vabysmo) is FDA-approved and works by targeting two pathways (VEGF and Ang-2) to reduce leakage, potentially allowing longer dosing intervals than older medications.
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Aflibercept 8m (Eylea HD) is an FDA-approved higher-concentration formulation of aflibercept 2mg, potentially allowing longer dosing intervals.
All of these medications are injected at intervals of one month or longer depending on the specific case. All of these medications are considered safe and effective.
Anti-VEGF injections do not cure wet AMD. The injections reduce bleeding and fluid leakage behind the retina but ongoing injections are usually needed to control the disease regardless of which medication is injected. Your retina specialist will talk to you about what to expect over the course of treatment.
Photodynamic therapy (PDT) is an additional treatment sometimes used for treatment of wet AMD. PDT by itself is not as effective as anti-VEGF medicines, but in selected cases, PDT combined with anti-VEGF therapy can provide good results and reduce the number of injections needed to control the disease. PDT consists of intravenous injection of a medicine called Verteporfin, followed by a laser treatment that activates the drug in the area of leaking blood vessels behind the retina.