Age-related macular degeneration - what you need to know
Age-related macular degeneration (AMD) is the most common cause of severe visual impairment in older adults in the UK and left untreated can have a profound impact on those suffering from it.
In our latest Ask the Expert article, Mr Hadi Zambarakji, Consultant Ophthalmologist talks about macular degeneration.
First of all - what is the macula?
The macula or macula lutea (from Latin macula, "spot" + lutea, "yellow") is a part of the retina responsible for central vision. So patients with macular problems tend to have poor central vision, but normally maintain good peripheral vision.
What is age-related macular degeneration?
The two main types of age-related macular degeneration are dry and wet age-related macular degeneration (AMD).
Dry AMD develops when the cells of the macula become damaged by a build-up of deposits called drusen. It's the most common and least serious type of AMD, accounting for around 9 out of 10 cases. Dry age-related macular degeneration progresses slowly and vision loss is gradual, occurring over many years. However, an estimated 1 in 10 people with dry AMD go on to develop wet AMD.
Wet AMD develops when abnormal blood vessels form underneath the retina and result in bleeding and leakage of fluid into the macula, thus affecting the vision fairly rapidly.
Wet AMD is more serious than dry AMD and without treatment, vision can deteriorate within days.
Nevertheless, severe visual loss may occur in both conditions.
What are the symptoms of age-related macular degeneration?
AMD is a painless condition that can cause loss of central vision, and usually affects both eyes but not necessarily to the same degree. In AMD, central vision becomes increasingly blurred, which means patients find:
- it difficult to read
- difficult to recognise people’s faces
- colours appear less vibrant
AMD doesn't affect your peripheral vision (side vision), which means it will not cause complete blindness.
Patients coming to my clinic may present acutely with loss of central vision and distortion of central vision, but some patients’ vision only deteriorates slowly. In some cases where only one eye is affected, symptoms may go unnoticed for several months as the patient may be relying on the fellow eye. This is particularly true if a patient has a lazy eye. Patients are therefore always advised to test each eye separately by covering each eye in turn, and to have regular eye tests at their Optometrist.
When should I see a doctor?
You should seek medical advice or see your Ophthalmologist if you have noticed a sudden drop in your central vision, or if you notice distortion of straight lines in your central vision.
I advise my patients to test each eye separately and I give my patients the Amsler Grid to test their central vision for any distortion. Another way of doing this is to look at a straight line such as the edge of a door to look for a bend in its centre.
It’s also important to see your Ophthalmologist for a baseline examination for macular degeneration if you have a strong family history of AMD to identify early signs of the condition. Treatment with high dose anti-oxidant vitamin supplements and Lutein at this stage will reduce the risk of the condition progressing and severe loss of vision.
What treatments are available?
The first step is prevention.
Life style changes such as avoiding smoking and eating a diet rich in fish and green leafy vegetables are recommended. In patients where one eye has lost vision due to AMD or where both eyes have signs of AMD (without necessarily having lost vision), anti-oxidant vitamin supplementation and Lutein supplements can reduce the risk of the condition progressing and severe vision loss. A detailed ocular examination by an Ophthalmologist is necessary at this stage to identify patients who would benefit from oral supplements.
There's currently no cure for either type of age-related macular degeneration, however with dry AMD, we treat the patient to make the most of their remaining vision – for example, low visual aids such as magnifying lenses can be used to make reading easier if given before the central vision is severely affected.
In the case of patients with wet AMD, treatment with intravitreal injections called anti-VEGF (anti vascular endothelial growth factor) injections can be administered with the aim of preventing further blood vessels developing and stopping the vision from getting any worse.
The management of age-related macular degeneration continues to be a fast changing field with newer developments being studied including radiation therapies and surgical options for very advanced disease. Unfortunately, current treatments do not reverse dry macular degeneration.
How much does treatment cost?
An initial consultation with Mr Zambarakji costs £180 for self-pay patients.
The package price for an anti-VEGF intravitreal injection (Eylea) is £1,350 per treatment* (which covers the hospital and consultant charges, including drugs and OCT scans).
*Price correct as of May 2017 but may be subject to change. Price excludes the cost of investigations such as OCT scans and fluorescein angiography.
How successful is treatment for age-related macular degeneration?
Visual outcomes are most encouraging and show that approximately 30% of patients treated by injections will gain some vision, 95% will maintain stable vision but a small proportion will have a decline in vision. Overall, treated patients will achieve an average gain of 9 letters or almost 2 lines of vision on a visual acuity chart.
What about patients with advanced (end-stage) age-related macular degeneration?
I would refer patients with advanced AMD (untreatable with injections) to the Macular Society where they can seek additional support, and I would also offer to register them as sight impaired. This would usually instigate a home visit by a specially trained health care professional to assess how well the patient is coping at home and if there are changes required in the home environment. For example the adequacy of things such as lighting, flooring, hand-rails, oven, bathroom, kettle would be assessed, but patients would also be given access to talking books and newspapers.
There is extensive evidence that supports the importance of genetic risk factors for age-related macular degeneration, thus supporting the view that a family history of age-related macular degeneration is a risk factor. In the not too distant future, I would expect that we would have available genetic testing kits to estimate the risk of developing age-related macular degeneration in particular when risks are calculated based on a combination of factors including genetic factors and lifestyle such as smoking and diet.
Mr Zambarakji holds clinics at The Holly Private Hospital on Thursdays. An initial consultation costs from £180.
To book a consultation, call our friendly appointments team on 020 8936 1201.
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