Age-Related Macular Degeneration

The exact cause is not known but cells in the macula break down due to the aging process, hence the term Age-Related Macular Degeneration (ARMD). Family history of ARMD and smoking tobacco are the known important risk factors. Less commonly, macular degeneration can occur in severely short-sighted people (high myopia) or in people with certain inflammatory and genetic conditions.

There are no symptoms in the initial stages, but assessment of the macula can reveal drusens, tiny yellowish deposits caused by the failure of the macula to get rid of its waste products. As the condition progresses, drusens increase in number and enlarge in size.

As the macular cells begin to disintegrate symptoms of blurred vision become noticeable. This especially affects the ability of people to see what is directly in front of them. Reading, writing and close work such as knitting is affected the most. As the disease progresses, people experience significant vision loss in the centre and are unable to recognise faces. The peripheral retina is never affected. Therefore, people never experience complete loss of vision as peripheral/side vision remains intact.

ARMD begins as the Dry type, progresses over decades, with approximately 10% of the patients developing Wet ARMD. In Wet ARMD, there is a growth of leaky blood vessels that waterlog the Macula with fluid and/or blood. This can lead to a rapid decline in their vision. So, Wet ARMD is not a type but a specific abnormality that develops in patients with ARMD. In Dry macular degeneration, the light-sensitive cells in the macula slowly break down, leading to gradual blurring of the central vision. As it gets worse, the macula becomes increasingly thin and the central blurred patch increases.

In the Wet form of macular degeneration, patients develop fragile and leaky blood vessels. This leads to leakage of fluid and blood in the macula hence the term ‘Wet’. If untreated, it leads to permanent damage to the macula and formation of a scar. Wet macular degeneration can happen suddenly leading to rapid loss of sight.

Patients with wet ARMD require prompt treatment. Delay in treatment can cause rapid decline and irreversible loss of central vision. Patients with dry ARMD, on the other hand, require assessment, advice and regular checks.

Mr Patwardhan uses the latest swept-source technology and multi-modal imaging to create a detailed picture of the macular structure and the vascular network. The imaging involves taking series of pictures using Topcon Triton camera. This new technology allows instant diagnosis of wet ARMD in almost 80% cases without needing any additional tests.

Wet macular degeneration is treated by injection of anti-vascular endothelial growth factor (anti-VEGF) drug in the eye. Beovu, Lucentis, Eylea and Avastin are the drugs available in this category. Anti-VEGF drugs work on leaky blood vessels to help reduce fluid in the macula. These drugs are injected into vitreous humour (gel at the back of the eye) under local anaesthesia.

All anti-VEGF drugs work equally well and have similar risks attached. However, the duration of treatment interval varies. The use of Avastin is considered unlicensed when used for macular conditions. This is because Avastin is licensed for use as intravenous injection to treat certain cancers. When a fraction of the drug is used as an injection into the eye it produces the same effect as the licensed anti-VEGF drugs.

The Anti-VEGF drug is injected into the eye under local anaesthesia. You will receive monthly injections for the first 3 months. After 3 months, injections are given at a regular interval. The interval between the injection is determined by the disease activity. At every visit you will require an eye assessment and an OCT scan to assess the response. How many injections are needed depends upon how aggressive the disease is. Patients with a more aggressive form of Wet AMD will need more frequent injections.

With regular assessment and treatment, approximately 90% of patients will experience success in preventing vision loss and almost 30% of patients will notice sustained improvement in their vision at the end of two years. The treatment does not cure the condition but prevents rapid loss of vision. The injection carries a small risk (0.3%) of sight-threatening infection, endophthalmitis. There is a small risk of developing glaucoma (increased pressure in the eye) or cataract (cloudy lens). With frequent injections there is a small risk (1-2%) of cardiovascular events such as heart attack and stroke.

Mr Patwardhan offers regular assessments using multi-modal imaging to patients with Dry macular degeneration. The assessments help in understanding the severity of the condition and monitoring progression of the disease. These assessments are also vital in diagnosing Wet ARMD at an early stage, and prompt intervention in these cases can prevent significant vision loss. Please contact Mr Patwardhan’s secretary to make an appointment for assessment.

Unfortunately, there is no treatment or cure for dry ARMD. Giving up smoking reduces the risk of severe sight loss by 30%. Wearing sunglasses to protect the eyes from sun’s rays and eating a healthy diet rich in antioxidants such as green leafy vegetables and citrus fruits may be beneficial. Age Related Eye Disease Study 2 (AREDS 2) showed that supplements containing Vitamins C (500 mg), Vitamin E (400 IU), Lutein (10 mg), Zeaxanthin (2 mg) and Zinc (80 mg) taken daily may benefit in slowing down the disease but it does not prevent ARMD from advancing. These supplements can be purchased from health shops or pharmacies. Smokers or ex-smokers should avoid any supplements containing Beta Carotene due to risk of lung cancer.