Macular Degeneration

What is Macular Degeneration?

Age-related Macular Degeneration (AMD) is one of the most common causes of visual loss. Usually affecting patients over the age of 50, the number of cases increases with age each year. The Macula is found at the back of the eye and is the central and most sensitive spot on the retina. Vision loss occurs as this spot becomes damaged, reducing the clarity of the central vision.

What is the Macula?

The macula is the central part of the retina. It has the highest number of photoreceptors (rods and cones) and as such is the most sensitive area of the retina. It is information from the macula which is used for fine detailed vision and the rest of the retina is used for the peripheral vision. Degeneration of the macula will make detailed tasks such as reading or even recognising people’s faces more and more difficult and in some advanced cases, impossible.

The disease affects people over the age of 50, becoming more prevalent the older we get. The biggest risk factors associated with AMD are:

• Age – around 15% of people over the age of 75 have some form of AMD
• Family history of AMD
• Smoking
• White Caucasian

What types of AMD are there?

AMD presents in two main forms, ‘wet’ and ‘dry’ AMD, and the pathology of the two are different.

Dry AMD

This is the most common form of AMD, during your eye examination the Optometrist will see small yellow deposits, or drusen, on the retina, as well as atrophy of the macula tissue.

Wet AMD

A less common form of AMD but is potentially the most visually devastating. Wet AMD is caused when abnormal blood vessel growth occurs under the macula. The macula becomes elevated from the other membranes causing tissue damage and loss of vision.

AMD only affects the macula and therefore only impacts the central vision, never resulting in complete loss of vision.

What treatment is there for AMD?

At the moment there is no cure for AMD. However recent studies have also shown some evidence that diet can help reduce the risk of AMD progression; Vegetables such as broccoli and kale are rich in certain pigments and antioxidants which aid in this. Quitting smoking will also help to reduce the risk of AMD development.

For people with AMD there some treatment options available to slow the progression of blood vessel growth. For some cases patient may be treated with Photo dynamic therapy (PDT) to minimise further deterioration to the vision.

Lucentis injections are another treatment approved by National Institute for Health and Care Excellence (NICE) for the treatment of wet AMD. Used to reduce the creation of abnormal blood vessels under the retina it is administered by injection directly into the eye. For best results most patients have a minimum of 3 injections but more may be required depending on the severity of the vessel growth. These injections have been proved to drastically improve the final quality of vision for patients with wet AMD. However the treatment is only effective in the early stages before the wet AMD has caused chronic scarring of the retina.