People living with age-related macular degeneration (AMD) can lose some or all of their central vision. The disease rarely affects the side (peripheral) vision, and for those whose central vision is affected, in some circumstances vision may be regained.
At the early stage of dry AMD, patients have tiny deposits under the retina that are visible to the ophthalmologist, called drusen. This stage usually has no symptoms. For early AMD, antioxidant vitamins (AREDS2 formula ), a diet rich in fruits, vegetables, and fatty fish per week may decrease the risk of vision loss and I have sometimes seen that the number of drusen may diminish over time.
A small clinical trial at Harvard has shown that some patients with very large drusen in the center of the retina can have their drusen size reduced and vision improved by a relatively high dose statin treatment. Statins are drugs prescribed by doctors to help lower cholesterol levels in the blood. A better understanding of the benefits and risks of this treatment will be obtained in a larger clinical trial.
Advanced Dry AMD
Some patients with AMD will have atrophy (wasting away) of light-sensitive cells: the rod and cone photoreceptors. Relatively large areas of atrophy are called “geographic atrophy.”
Currently, there is no treatment that brings back or replaces dead photoreceptors. Research with stem cells is showing promise in animal models. One form of stem cells comes from the patient’s skin, which can be genetically reprogrammed to become retinal cells! This process can help prevent immune rejection of transplanted cells. A few patients have had retinal stem cell transplants. So far they have not caused major complications, but effectiveness has not been proven.
[Advances in this form of regenerative medicine are promising, but a word of caution. Individuals seeking to participate in a clinical trial on stem cells can be vulnerable to promises of poorly designed, questionable studies. An account of three women who suffered severe vision loss as a result of a seriously flawed procedures—and how to identify legitimate clinical trials—is provided in the NIH Director’s Blog, in our Resources section below.]
The goal of most stem cell transplants in AMD patients has been to replace retinal pigment epithelial (RPE) cells rather than photoreceptors. The RPE is a layer of cells that support the health of photoreceptors. In AMD, the RPE is often damaged and can die. It is easier to replace RPE cells than photoreceptors because the RPE cells are easier to generate from stem cells, easier to surgically transplant, and do not need to connect to existing neurons in the retina in order to function.
For patients with wet AMD, caused by new, leaky blood vessels growing into the retina, lost vision can sometimes be regained following injections into the eye of what are known as anti-VEGF antibodies. These include the drugs brolucizumab (Beovu®) aflibercept (Eylea®), and ranibizumab (Lucentis®). These medications reduce leakage from the blood vessels, allowing the retina to “dry up” to its normal condition, which can improve the vision.
Other Treatments that May Improve Vision in People with Macular Degeneration
Many patients can have their vision improved without treating their retinas. Cataract, which is a clouding of the lens inside the eye, can reduce the amount of light getting to the retina. Most evidence indicates that there’s no risk of making AMD worse by having cataract surgery.
Low Vision Devices
Glasses or low vision devices that magnify and increase lighting can be helpful. Some patients like to wear yellow tinted glasses to increase contrast.
There are also patients who have tiny telescopes implanted into an eye (implantable miniature telescopes) to magnify images. These are put into the eye in place of the natural lens. Until recently, they were only available to patients who had not had cataract surgery, but there is now a clinical trial to test them for patients who have already had cataract surgery.
Macular degeneration is an area of intensive research. The discovery of VEGF as an important driver of wet AMD, by American scientists supported by the NIH and private foundations, has led to improved vision in millions of patients. Future “bench to bedside” research will lead to better treatments to prevent and reverse AMD.