Everything we look at directly is identified by the macula, the area on the retina at the back of the eye responsible for sharp central vision. When the macula is damaged in some way there is a gradual loss of central vision. Peripheral vision remains intact, but it becomes difficult to see fine details both close up and further away. This age-related macular degeneration (AMD) is a leading cause of vision loss in people over the age of 50. Because the vision loss is gradual, many people are unaware that they have macular degeneration initially. Your optometrist is usually able to detect the early signs, often before you experience visual problems, so regular visual examinations are important.
TYPES OF AMD
There are two types of AMD, dry and wet. Dry AMD is more common than wet AMD.
In most cases dry AMD is diagnosed when tiny white spots are noticed on the retina due to a thinning of the macula. These are called drusen (pebbles) and they represent tiny deposits of cellular waste products and immune system proteins. Over time the macula may become thinner and the drusen may increase in size or number, increasing the risk for the development of intermediate AMD. Although symptoms are not generally present at first, a blurred spot in central vision may begin to appear.
Wet AMD is less common but more serious than dry AMD. It tends to progress more rapidly and cause more severe vision loss. Wet AMD occurs when new, abnormal blood vessels grow under the retina toward the macula. Because these blood vessels are abnormal, they break and leak blood or other fluids, damaging the macula and causing it to lift away from its base.
WHO IS AT RISK FOR AMD?
Anyone can develop AMD, but lifestyle and diet are major factors in an individual’s risk. People most likely to develop AMD eat a diet high in saturated fat, are over 50 years in age and smoke. Conditions such as high blood pressure and heart disease may increase the risk. Family history has a role to play, with genetic factors influencing when AMD starts and how quickly it progresses.
Presently, there is no specific treatment for the dry form of AMD. However, there may be some benefits from taking a certain combination of nutritional supplements. While not a cure, a large study found that the progress of the condition was slowed by the daily intake of vitamin C, vitamin E, lutein, zeaxanthin, zinc and copper. Ask your optometrist for recommendations and advice on the taking of supplements.
To help treat wet AMD, there are medications which help reduce the number of abnormal blood vessels in the retina and slow down any leaking from blood vessels. Laser surgery may also be effective to treat some types of wet AMD. Discuss appropriate treatments with your optometrist who will refer you to an ophthalmologist if necessary.
Modifications to lifestyle and eating eye-healthy foods can reduce the risk of AMD progression. A healthy diet including fatty fish such as salmon and mackerel as well as dark leafy greens and yellow and orange fruits and vegetables can help, too. Giving up smoking is essential. Sunglasses are advisable when out in bright light.
Most importantly, regular eye examinations, particularly if there is a family history of AMD, are critical in detecting and treating AMD as early as possible, as well as monitoring the progress of the condition over time. If a significant amount of central vision has been lost, your optometrist can refer you to a low vision specialist or offer suggestions to help you make optimal use of your remaining vision.
WHAT I WISH PEOPLE UNDERSTOOD ABOUT MY VISION LOSS
A group which offers support to people with AMD has listed a number of personal experiences highlighting issues regarding this condition.
“Just because our vision changes doesn’t necessarily mean our interests do. People may assume that sight-related hobbies are no longer accessible or interesting with vision loss, so we are not invited on shopping trips or to watch a sports match. Things do change, but there are almost always ways to compensate and adapt when it comes to activities we enjoy.”
“It can feel socially isolating. It can make me feel awkward and self-conscious when some-one can see me, but I can’t see them. It helps when people acknowledge me personally and identify themselves, instead of me trying to figure out who greeted me!”
“The things we can and can’t see can sometimes be confusing, even for us. I can identify most colours in a general sense but often can’t distinguish certain colours. It can be difficult to explain to people why I can see certain things and not others when I can’t really understand it myself.”
“I can have bad and good vision days, depending on whether it is sunny or cloudy, the time of day, indoors or outdoors, my eyes are tired, or factors I haven’t even thought of, causing my eyes to play tricks on me.”
“It’s not something I dwell on daily. Gradual vision loss, as the name suggests, does not happen suddenly. It is similar to aging which happens over time without me noticing it. Sometimes I am surprised when my optometrist tells me my vision has worsened because I hadn’t been aware of the change.”
“Some of us use mobility aids like canes and dogs, and some of us don’t. There can be people who have the exact same vision who move about the world completely differently.”
“Most of us lead regular, happy lives. I have dealt with my share of sadness over having AMD, but sadness is definitely not the word that comes up for me when thinking about my life. Challenge? Sure. Adventure? Yes. Joy? Absolutely.”