Canterbury Eye Specialists provides monitoring and treatment of macular degeneration, which includes eye injections.
Macular degeneration is a disease that affects the central retina (the macula). We can compare the human eye to a camera. The retina is like a photographic plate or film that sits at the back of the eye and captures light to form images -sending them via the optic nerves to the brain.
The macula is the central and most sensitive area of the retina, it collects highly detailed images at the centre of your vision in each eye, this allows you to read, drive a car, recognise faces and see objects in fine detail. When the cells of the macula deteriorate, the quality of the images received by the brain is affected.
Macular degeneration is also known as age related macular degeneration. Macular degeneration usually occurs in patients over the age of 50 years. Macular degeneration becomes more common with increasing age. We also know that there are inherited genes that increase your risk of developing macular degeneration. Another major risk factor is smoking.
Symptoms of Macular Degeneration
- Blurred vision
- Distorted vision
- Difficulty reading
A black patch in the centre of vision, sometimes more noticeable in low light levels
These symptoms can come on suddenly or appear gradually.
Types of Macular Degeneration
Dry Macular Degeneration
Dry macular degeneration is the most common form of macular degeneration. In most cases it progresses slowly over time. Yellow deposits form in the deep layer of the retina, these are known as drusen. The surrounding retinal cells slowly die, eventually permanently affecting the central reading vision. Unfortunately there is no proven treatment. There is a new laser, the 2RT laser, which has been shown to be promising for certain subsets of dry macular degeneration, however it is not an accepted and proven treatment and further studies are being undertaken.
Dry macular degeneration increases your risk of developing wet macular degeneration. Patients are advised to monitor their vision with an Amsler vision chart.
Wet Macular Degeneration
This is a less common but more aggressive form of macular degeneration. Wet macular degeneration is caused by an abnormal blood vessel that grows into the retina. It leaks fluid and blood into the retina causing swelling and scarring of the macula. This can cause rapid, severe and irreversible loss of central vision. Fortunately wet macular degeneration is very successfully treated with injections of medications (anti-vascular endothelial growth factor) into the back of the eye (the vitreous).
A protein called Vascular Endothelial Growth Factor or VEGF, is responsible for the growth of the new blood vessel. To stop or slow this process, various drugs that block the protein, called anti-VEGF agents, can be injected into the eye.
Diagnosis of Macular Degeneration
- Dilated eye or retinal examination
- Ocular coherence tomography/OCT scan
- Ocular coherence tomography-angiography/OCT-A scan
These injections are very successful in treating wet macular degeneration. The earlier the abnormal blood vessel is treated the better, giving you the best chance of retaining good vision. If the injections are started early enough treatment can improve vision. Generally the injections are continued long term. The average time between injections is 7 weeks, although sometimes they can be extended up to 4 months.
Do Intravitreal Injections Hurt?
In general, patients describe the injections as being pain free. The key is adequate local anaesthetic and a better tolerated antiseptic, chlorhexidine. Patients are usually very relieved after their first injection as they are not as unpleasant as they had been expecting.
Does Macular Degeneration Cause Complete Blindness?
No! Macular degeneration causes loss of central vision but not peripheral vision. Patients will not go completely blind, whilst it may be difficult to read or drive, patients can still see well enough to move around their homes and maintain an independent life.
Prevention of Macular Degeneration
It is possible to reduce the risk of losing sight from macular degeneration by adopting a healthy lifestyle and regularly having your eyes tested and macula checked by an eye health professional.
The risk of developing the late effects of macular degeneration can be reduced by nutritional supplements. The AREDS and AREDS 2 trials have shown the benefit of antioxidant and other supplements in reducing the rate of deterioration of dry macular degeneration into wet macular degeneration by 20-30%. However, these benefits are only seen in people with certain types of moderate to severe dry macular degeneration and not in those with milder forms.
For people with the mild form of dry macular degeneration or, in those wishing to minimise the risk of developing macular degeneration, in whom nutritional supplements have not been shown to be effective, a healthy diet with a high content of green leafy and other brightly coloured vegetables, fish and nuts is recommended.