Macular degeneration’s ravages
The degenerative condition will affect roughly 10 per cent of adults over the age of 65 and the prevalence grows with age.
An Amsler grid can help people monitor changes in central vision that may signal age-related macular degeneration.
Some of the hardest physical compromises of aging affect our eye function — our vision. Of these, the most common, apart from cataracts, is macular degeneration, which affects roughly 10 per cent of adults over the age of 65 and up to 30 per cent of those over 75.
In macular degeneration, the central part of the retina –– the macula, which allows us to see detail, read and recognize the faces of friends and family –– gradually deteriorates until the central vision is essentially lost. The effects on a patient’s life are immense. As Phil Hooper, an ophthalmologist and immediate past-president of the Canadian Ophthalmological Society says, “Macular degeneration can be extremely frustrating for patients. If you lose much of your capacity to read, that will make a great difference in anyone’s life. And many patients find that when they go out, they often fail to recognize the faces of their friends. They come to fear that their friends will think they’re snubbing them, and this can lead to social withdrawal.”
A slow creep
Macular degeneration begins insidiously.
At first, you may notice nothing, though the eye is already, in this initial stage, starting to accumulate tiny yellow protein deposits called drusen under the macula. In an intermediate state, as the drusen enlarge, more obvious compromises of vision begin. It may become harder to read in low light and driving at night might become more challenging. The eye might not pick up as much detail as it did before. If one has to look briefly into very bright lights such as car headlights, the eye might take longer to recover from the glare.
In advanced stages, when the damage to the macula becomes more severe, the centre vision becomes smudgy. Reading can now become impossible. Vibrant colours can now appear muted, faded. And, as mentioned, even recognizing faces can become challenging.
Eventually, the macula will darken into a scotoma, a blind spot in your field of vision, though the peripheral vision, at the edge of the visual field, remains intact.
That peripheral vision is to be cherished, but the loss of central vision is disastrous. People whose work requires reading may have to change careers. Many people can no longer drive, causing a loss of independence. Social interaction can become awkward because one misses the micro facial expressions that convey human emotions. And, as Hooper noted, one can even fail to recognize a close friend or family member. All these factors can have powerful psychological effects, with embarrassment, depression, anxiety and an impulse to withdraw socially often coming into play.
The two stages
Macular degeneration has two stages. The first, dry stage has the less severe symptoms, but if the condition progresses to the wet stage, which sees fragile blood vessels grow under the macula and leak fluid or blood, rapid deterioration can occur over mere days or weeks. This wet form occurs in 10 to 15 per cent of cases. Wet macular degeneration’s classic hallmark is a tendency of straight lines to appear crooked or wavy — an effect easily seen when looking at doorframes, blinds or graph lines. (Clinicians may give patients an Amsler grid, a simple square chart with a grid pattern that helps detect these distortions early on.)
Age is not the only risk factor. Head injuries, diabetes, infections and some diet deficiencies can play a causal role. There is a genetic element in some cases, though sporadic cases also occur.
Prevention strategies
Hooper mentions a number of strategies to reduce one’s susceptibility to this disease.
“One thing we advise is a heart-healthy diet. The Mediterranean diet is a good one. You want a diet rich in antioxidants and low in saturated fats.
“And if the patient is a smoker, [they] really should stop. Smoking accelerates the advance of the disease.”
He adds that blood pressure should be controlled, though its influence on the disease is probably not as great as diet and smoking.
If you are diagnosed, there are a number of drugs your ophthalmologist can prescribe and more coming down the tube. According to Hooper, “The range of drugs that will become available should be more effective for both the wet and dry forms of the disease.”
Though sunglasses are sometimes mentioned as a means of preventing the development of the disease, Hooper says research does not give strong support to the notion.
Developing macular degeneration does not necessarily mean that you will become legally blind. “It all depends on how long you live with the disease,” he says. “A quarter of those who live into their 90s will become legally blind.”
Hooper is delighted that the general population seems increasingly aware of macular degeneration. “This can only help,” he says. “With increased awareness, it’s less likely that people will delay seeking treatment until the disease is relatively advanced. In medicine, that’s always an advantage.”
Charles Enman is a senior who has had both corneas replaced and is working hard to avoid macular degeneration.
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