Age-related macular degeneration is one of the most common causes of vision loss in developed countries, affecting between 30 million and 50 million people worldwide.
As the name suggests, age-related macular degeneration (AMD) is most common in people over 60, and more people are suffering from AMD as the population ages. About 90 per cent of AMD cases are dry AMD, for which there is no good treatment today.
What Is Macular Degeneration?
AMD can make things like reading, watching TV, driving or recognising faces difficult.
Other symptoms include:
- Seeing straight lines as wavy or crooked
- Objects looking smaller than normal
- Colours seeming less bright than they used to
- Seeing things that aren’t there (hallucinations)
AMD isn’t painful and doesn’t affect the appearance of your eyes.
The first symptom is often a blurred or distorted area in your vision
If it gets worse, you might struggle to see anything in the middle of your vision
The retina is the nerve tissue lining the inside of the eye that starts the conversion of light into vision. At the centre, in the back of the retina, is the macula, a small area about 5.5 millimetres in diameter that is responsible for central vision, which is essential for tasks such as reading, driving and facial recognition.
The macula is densely packed with photoreceptor cells called rods and cones that react to light and send electrical nerve impulses to the optic nerve and into the brain.
Behind the photoreceptors is another layer of cells called retinal pigment epithelium (RPE), which support the rods and cones by delivering nutrients from the bloodstream and removing waste that the rods and cones generate.
In AMD, the RPE cells stop performing their support functions and the rods and cones die, resulting in a loss of central vision. Dry AMD typically progresses over several years.
In the less common wet AMD, something (scientists aren’t sure what) spurs abnormal blood vessel growth, and central vision can be lost in a matter of weeks or days.
How Is Macular Degeneration Treated Without Stem Cells?
- Dry AMD – there’s no treatment, but vision aids can help reduce the effect on your life.
- Wet AMD – you may need regular eye injections and, very occasionally, a light treatment called “photodynamic therapy” to stop your vision getting worse.
The most common form is “dry” AMD, which causes gradual vision loss. Some people go on to develop “wet” AMD, so-called because fragile blood vessels start to grow as the body attempts to repair the damaged macula. The new vessels are leaky and bleed easily, causing more damage.
Scientists in the UK have reported on the results of pioneering operations in 2 patients with age-related macular degeneration (AMD), a major cause of sight loss in older people.
Researchers used a stem cell patch to repair the damaged membrane at the back of the eye called the retinal pigment epithelium (RPE).
After a year, both patients were able to read again with glasses using the affected eye, although their vision wasn’t perfect.