Macular degeneration

This condition is also known as Age Related Macular Degeneration (ARMD) and is a condition that usually affects older adults. It results in a loss of vision in the centre of the visual field (the macula) due to damage to the retina.

It is a major cause of visual impairment in older adults (>50 years). Macular degeneration can make it difficult or impossible to read or recognize faces, although enough peripheral (side) vision remains to allow other activities of daily life.

Age-related macular degeneration begins with characteristic yellow deposits in the macula (central area of the retina, which provides detailed central vision) called drusen. Most people with these early changes (referred to as age-related maculopathy) have good vision. People with drusen can go on to develop advanced AMD. The risk is considerably higher when the drusen are large and numerous and associated with disturbance in the pigmented cell layer under the macula.

There are two forms known as “dry” and “wet” macular degeneration.

The dry (non-exudative) form leads to a slow decline of central vision due to atrophy (wasting away). There are limited treatment options for this form but there is very active research to the cause and treatment.

Certainly there is good evidence for ceasing smoking, lowering cholesterol and a diet rich in green leafy vegetables. Studies have also show some protection can be achieved in high risk groups with the intake of certain vitamins such as Macuvison.

The wet (exudative) form is more severe and is due to a leak and bleeding from blood vessels under the macula. This can lead to sudden and devastating vision loss. Over the recent years new treatment techniques such as anti-VEGF agents have become available, that for the first time, reverses the damage and restores vision. The prognosis is better if treated early.

Screening of central vision disturbance/distortion can be helpful to diagnose early disease.

The Amsler Grid test is recommended for the at risk group of 'wet' macular degeneration. Those who are at greater risk of developing ARMD include those who:

· Have a family history of ARMD.

· Have already developed ARMD in one eye already.

Proper diagnosis of ARMD involves test using specialised equipment.