written by Dr. William McSwain
In the United States, age related macular degeneration (AMD) is the leading cause of severe central vision loss in people over the age of 50. As its name implies, AMD involves degeneration of the macula (the central part of the retina) and is associated with increasing age. Symptoms of AMD involve progressive loss of central vision in one or both eyes. Loss of central vision interferes with tasks requiring fine detailed vision such as reading, driving, or recognizing faces. Peripheral vision is unaffected by AMD. Vision loss most often progresses slowly but may occur rapidly in some cases. AMD can occur in anyone over the age of 50, but risk factors include advanced age, a positive family history, smoking, and cardiovascular disease. It tends to be more common in women and people of European descent.
There are two main types of AMD: dry and wet. Typically, dry AMD begins first and may progress to wet AMD. Most people who have wet AMD also have components of dry AMD. Wet AMD (also known as neovascular or exudative AMD) indicates the presence of choroidal neovascularization which means that new abnormal blood vessels have grown into the macula causing bleeding and swelling that interferes with vision. Both dry and wet AMD can profoundly decrease vision but wet AMD progress more rapidly and needs to be treated urgently to prevent permanent vision loss.
The diagnosis of AMD involves a combination of the patient history, dilated exam, and testing including high definition photography, optical coherence tomography (OCT), and fluorescein angiogram (FA). Photos of the retina are taken at your initial appointment to monitor for future progression. If wet AMD is suspected, an OCT or FA may be performed to identify swelling and bleeding in the macula from the growth of abnormal blood vessels.
Initial management of AMD involves taking AREDS nutritional supplements. These supplements have been shown in a randomized controlled trial to decrease the risk of progression of moderate AMD by 25%. This is a great result from something as simple as taking vitamins. I recommend using Preservision AREDS2. It can be purchased from a pharmacy without a prescription. The most important ingredients in these vitamins are thought to be lutein and zeaxanthin. If you are or have ever been a smoker, make sure you only use supplements that say “AREDS2 Formula” and do not include vitamin A.
Smoking causes AMD to progress more rapidly so if you are a smoker, try to quit or cut back as much as you can. Continuing to smoke could cause you to lose your vision permanently. Other lifestyle modifications you can make include regular exercise and eating nutritious foods including leafy green vegetables and fish.
You will be given an Amsler grid for home monitoring of your AMD. Check the Amsler grid with each eye at least once a week and contact us immediately if you notice any changes in the appearance of the grid. Changes on the grid could indicate you have developed wet AMD.
The treatment for the wet form of AMD used to be extremely limited. The only options involved invasive surgery or aggressive laser to the macula that left many patients without much central vision. You may have older relatives who lost their vision or became blind because of AMD.
Fortunately, the treatment of wet AMD has revolutionized the field of ophthalmology stemming from the blockage of vascular endothelial growth factor (VEGF). VEGF regulates the growth of abnormal blood vessels in the eye. Several injectable drugs that target VEGF have been developed to treat wet AMD.
The most commonly used anti-VEGF medications are Avastin, Lucentis, and Eylea. These medications are easily the most successful way to maintain or even improve vision in people with AMD. They are delivered through an injection into the vitreous, the jelly-like substance within the back of the eye. These injections often need to be repeated on a regular basis, sometimes for many years. You will be given anesthetic prior to the injection to make it as pain-free as possible. The injection only takes a few seconds and is done with a very small needle. After the injection, your vision may be decreased but should recover in the next 1-2 days. Your eye may appear red or have a small spot of bleeding at the injection site, but this should clear in a few days. You may notice black swirls in your vision for a few weeks caused by the medication floating in the vitreous jelly.