Age-Related Macular Degeneration (AMD)

The dry form of AMD is a gradual process where the retinal cells die resulting in worn-out patches known as “geographic atrophy”. These enlarge and can cause slowly progressive loss of central vision. There is currently no treatment available in Australia for this form of AMD, although there may be treatments available in the near future.

The wet form of AMD is characterised by a more rapid loss of central vision. This is the result of small blood vessels growing underneath the retina. This process is termed Choroidal Neovascularisation and the abnormal blood vessel may bleed or leak, and scar tissue can form. It is treatable with intravitreal anti-VEGF injections.

In the early stages there may be no symptoms. One of the earliest manifestations is a need for brighter light when reading. In the late stage blurred or distorted vision is commonly reported. Near (reading) vision is often affected more so than distance vision. AMD damages the macula which is responsible for detailed vision such as reading and the ability to recognise faces. The peripheral vision is not affected.

Smoking is the most important modifiable risk factor for AMD development and progression. Smokers have a three-fold increased risk of developing AMD compared with people who have never smoked. Stopping smoking can halve this risk.

Dietary measures may also reduce the risk:

• eat a healthy, well-balanced diet
• eat dark green leafy vegetables and fresh fruit daily
• eat fish two to three times a week
• choose low glycemic index (low GI) carbohydrates instead of high GI
• eat a handful of nuts a week

Vitamin Supplements & the Age-Related Eye Disease Study (AREDS)
Supplements may be of value in patients with Intermediate AMD where there is a substantial collection of debris (drusen) at the macula or in patients who already have late AMD in one eye. In patients with Early AMD the risk of progression to late AMD is lower and supplements are not of proven benefit.

The Age-Related Eye Disease (AREDS) studies showed that supplementation reduced the risk of progression to wet AMD by 25% in high risk individuals, but does not prevent progression of dry AMD.

There are a number of commercially available AREDS supplements on the market in Australia. Talk with your ophthalmologist about whether supplements will help in your case, and which ones are recommended.

First-line therapy since 2007 has been with intravitreal injections of anti-vascular endothelial growth factor (anti-VEGF) drugs. These drugs do not cure the disease but aim to suppress the growth and leakage of the abnormally leaking and bleeding blood vessels. They stabilise vision in most cases, and up to a third of patients experience some improvement in vision.

Treatment should be started with as little delay as possible as these agents cannot reverse scarring or retinal thinning which occurs in many untreated cases.

The most commonly used agents are Lucentis (ranibizumab) and Eylea (aflibercept) and Vabysmo (faricimab). Numerous new drugs are in development. Previous treatments such as laser and photodynamic therapy are rarely used nowadays.