The macula is located at the back of the eye. It is the central and most sensitive part of the retina, providing the highest resolution for your central vision. The macula is used for reading, driving, and recognizing faces. Age-related macular degeneration (AMD) affects the macula, causing blurred or distorted central vision while the side or peripheral vision remains unaffected. Retinal disorders like AMD are more common in mature eyes, and macular degeneration is the leading cause of blindness in North American adults over the age of 55. While there is no cure, early detection and preventative measures can delay or reduce vision loss.
There are two types of AMD: dry and wet, with the dry form being more common. Dry AMD is also the milder form, where there is a gradual degeneration of the retinal tissues that make up the macula, and symptoms generally develop slowly. In the wet form, there is a sudden leakage, or bleeding, from weak blood vessels under the macula, and symptoms develop rapidly. Wet AMD accounts for approximately 10 per cent of all cases, but the dry form can develop into the wet form over time.
Patients don't experience any pain with AMD. In the earliest stages, macular degeneration is entirely symptom free but can be detected during routine eye examinations by your optometrist. Patients are often unaware of the condition, because many people with early AMD still have 20/20 vision in the affected eye(s). Also when AMD initially affects only one eye, the "good" eye will often compensate for the affected eye. While central vision becomes poor, peripheral vision almost always remains intact.
The most common initial symptom is slightly wavy or distorted central vision when performing tasks that require seeing detail. There may be a sense that there is dirt in the way of clear vision. This blurred spot cannot be corrected with eyewear. Over time, the damaged area may increase in size and interfere with reading and recognizing faces.
Although lost vision due to macular degeneration cannot be recovered, early diagnosis is important, as some cases may be treated with anti-VEGF injections to delay progression of the condition. Your optometrist may advise lifestyle modifications like exercising, quitting smoking, and wearing sunglasses to reduce UV radiation. Ocular vitamin supplements including lutein, zeaxanthin, and vitamins C, E and Zinc, can also assist in slowing the progression of AMD. Special low vision aids, magnifiers, and telescopes may be recommended or patients may be referred to CNIB (Canadian National Institute for the Blind), which operates vision enhancement clinics in Winnipeg and Brandon.
Lifelong UV protection and good nutrition are believed to play key roles in preventing macular degeneration. Living a healthy lifestyle by keeping your blood pressure down, reducing your intake of fatty foods, and avoiding smoking are all recommended. A diet high in antioxidants, such as those found in fruits and leafy vegetables, may help prevent AMD. Regular eye examinations are also important in the early detection of AMD, particularly for those with a family history of AMD as there are hereditary factors that increase risk.