What are the stages of AMD?
AMD is clinically classified into early, intermediate and late stages. It is possible to have AMD in one eye only, or to have one eye with a later stage of AMD than the other.
Early and intermediate AMD are characterised by:
- thickening and loss of normal architecture of Bruch’s membrane (the innermost layer of the choroid)
- formation of extracellular deposits composed of glycoproteins and lipids (drusen), which accumulate and spread over time in the retina.
Visual loss may be experienced by some people with intermediate AMD as drusen increase in size. However, most people will not have symptoms at this stage and the disease is often only detected during routine eye examinations.
Late stage AMD can present in two forms:
The atrophic form, also called Geographic Atrophy in which the drusen grow in size and number over time, leads to the death of photoreceptor cells in this central area (macula) responsible for the sharp central vision. This process results in a blurring or spotty loss of clear, straight-ahead vision, impairing the ability to read, drive and recognise faces. There is no approved treatment today for the atrophic form of AMD.
The neovascular form of AMD (also called wet AMD) occurs when abnormal blood vessels grow behind the macula. The new vessels are very fragile and can leak fluid and blood leading to rapid vision loss. Neovascular AMD is currently treated with frequent intra ocular injections of anti VEGFs.
AMD and quality of life
Developing AMD can be devastating to those who were independent and active prior to the onset of this disease. Their visual world gradually diminishes into a vague blur, making ordinary daily activities challenging as the loss of central vision appearing in the late stage of the disease can interfere with simple everyday activities, such as the ability to see faces, drive, read, write, or do close work, such as cooking or fixing things around the house. Research into the quality of life of people with AMD has shown that for late-stage AMD, between 50 and 60% decrease in quality of life is reported, more than that of dialysis and similar to that encountered with stroke or prostate cancer.
Quality of life impairment is often significantly greater when rated by patients than when estimated by treating ophthalmologists for the same condition.
According to the Office of National Statistics, over 3.8 million people are affected by AMD in the UK.
Find out more
Royal National Institute for the Blind: https://www.rnib.org.uk/eye-health-eye-conditions-z-eye-conditions/age-related-macular-degeneration-amd
Macular Society: https://www.macularsociety.org