The macula is in the middle of the retina which is a film lining the inside of the back of the eye. The retina is sensitive to light and sends electrical signals to the brain when light reaches it. The macula is essential for sharp, daytime vision including recognising faces, reading, using a computer and seeing colours clearly.
What is macular degeneration (AMD)?
Macular degeneration involves loss of structural integrity at the macula, this leads to deterioration in central vision but peripheral vision is not affected. Depending on the nature of the changes at the macula it is classified as ‘wet’ or ‘dry’. Dry AMD involves a build up of waste deposits (drusen), patches of abnormal pigmentation and areas of thinning at the macular. Typically, dry maculopathy is associated with a gradual loss of central vision. Wet AMD is the more aggressive form of macular degeneration and is related to fluid at the macula. A process called “choroidal neovascularisation” is involved, what this means is new blood vessels growing inappropriately just below the retina. This is a problem as the blood vessels can leak, in doing so they damage the macula and cause a rapid loss of central vision.
What are the risk factors?
The risk of having macular degeneration increases with age and a strong family history. Another significant risk factor is smoking; in fact you are three to four times more likely to get macular degeneration if you smoke. Cardio-vascular factors such as diabetes and high blood pressure can also increase risk of AMD.
Symptoms of macular degeneration may include...
o Increasing difficulty reading
o Distortion of straight lines i.e. they appear to be wavy
o Trouble distinguishing faces
o Black or missing patches in vision
What treatment is available for people with macular degeneration?
To date there is not a cure for macular degeneration but certain steps can be taken to limits it progression. For prevention of macular degeneration certain lifestyle choices are important, these include not smoking, exercising and having a healthy diet (see ‘nutrition’ below).
Your eye care specialist may recommend taking a supplement. It has been shown by long term studies AREDS and AREDS2 (Age-Related Eye Disease Studies) that supplements can be beneficial in cases of early to intermediate AMD. Supplements haven’t been shown to be useful in advanced macular degeneration or at the most early stages of AMD. AREDS/2 showed that people who took a regular high dose of specific nutrients showed a reduced risk of disease progression and a 20 – 25% delay in vision loss. The nutrients shown to be useful were Zinc, Vitamin C, Vitamin E, Omega-3, Selenium and Lutein/Zeaxanthin. For the benefits these nutrients must be combined according to a certain formula.
In the case of wet macular degeneration there is treatment available, again it is not a cure. Wet AMD involves leakage from blood vessels growing under the macula which damages it and can cause rapid vision loss. A drug that discourages growth of these new, leaky blood vessels is used to treat wet AMD. Reduction of inappropriate blood vessel growth leads to reduced leakage at the macular and subsequently less damage and preservation of vision. This medication is administered directly into the eye via injection.
Tips for a healthy macula
o Get the health of your eyes checked regularly
o Don’t smoke and avoid being around people smoking
o Look after your general health including your weight, exercise frequently
o Nutrition - Eat leafy green vegetables and fresh fruit daily, have fish two to three times a week and have a handful of nuts about once a week. Avoid excessive fat and oil and choose complex (low GI) carbohydrates.
o If recommended by your doctor / optometrist take an appropriate supplement
o Use an Amsler grid to self-monitor your macula
o Be sun-smart to avoid getting UV damage to your eyes, especially important while young
Early detection is very important. If you notice a reduction or any changes in your vision it is important you have your eyes examined. Detecting macular degeneration early allows steps to be taken that may slow disease progression and prevent vision loss.