Age Related Macular Degeneration (AMD) What is the importance of the macula?
The macula is a small area at the centre of the retina that allows us to see fine details such as central vision, activities such as reading and writing and appreciating colour vision.
What causes AMD?
Sometimes the delicate cells of the macula are damaged and stop functioning. The exact cause is not known although it tends to happen as people get older. This is called age-related macular degeneration. The most common types of macular degeneration are the dry [atrophic] and the wet [exudative].
The dry type is caused by aging and thinning of the tissues of the macula. The wet type results from the formation of abnormal blood vessels under the macula which leak fluid or blood and blur the central vision.
What are the risk factors for developing AMD?
- It most commonly occurs in patients over the age of 65; however it is also seen in patients 50 years and older.
- AMD may occur in all races but is more common in white patients.
- Smokers are at high risk of developing wet AMD.
- Patients with a family history of AMD are at risk.
Symptoms of AMD:
- Blurred or distorted central vision
- Words on a page look blurred
- Straight lines appear distorted
- Dark or empty areas appear in the centre of vision
This makes activities like reading, writing and recognizing small objects or faces very difficult.
How is AMD diagnosed?
A complete eye examination by an eye specialist is important. Special investigations to analyse the retinal layers and blood vessels, which include an OCT scan. The Oct scan will help distinguish between dry and wet AMD.
How is AMD treated?
Damage to the macula from the dry form is irreversible. Depending on the clinical findings some patients will benefit from low vision aids and a specifically formulated vitamin supplement to delay progression of the disease.
Wet AMD is treated with injections of Anti-VEGF medication into the eye that will improve and stabilize vision.
A diet with green leafy vegetables is advised.
Anti- VEGF eye injections:
Anti-VEGF drugs block the molecules that cause abnormal blood vessel growth, reducing the growth of abnormal blood vessels and slowing their leakage of blood and fluid. This procedure is commonly performed in the office. The eye is cleaned and sterilized before local anaesthetic drops are instilled to make the procedure pain free and comfortable.
The recent development of anti-VEGF medications have become a path breaking advance in the treatment of wet AMD.
Bevacizumab and Ranibizumab are two very useful drugs. Most patients will retain the vision they have and some will regain some of the lost vision after these treatments. The above doses generally take care of the acute need of treatment and no further injections are required, unless the condition changes over time.
Despite advanced medical treatment, most people with macular degeneration still experience some vision loss.
Your role in the management of your eye condition:
Regular monitoring of your central vision at home with an Amsler grid will help us detect progression in the early stages. Any abnormality or its progression must immediately be reported.