What is macular degeneration?
- This is a common condition, which occurs increasingly with older age.
- The patient has difficulty with tasks requiring that they see fine detail, such as when reading or recognising faces.
- The severity and rate of visual loss can be variable. While it may remain mild significant loss of central vision can occur.
- It affects detailed central vision by disturbing the part of the retina responsible for this called the macula.
It must be emphasised that macular degeneration tends only to affect central vision, sparing the peripheral vision. Therefore whilst a patient may not be able to read well, or recognise faces, the ability to walk about is not lost.
Main forms of macular degeneration
“Dry” - The macula slowly becomes weaker with atrophy (wearing away) of the ocular tissue required for sharp vision, especially when reading.
“Wet” - Vision is lost due to the development of abnormal blood vessels under the macula, which may bleed and leak fluid. The rate of loss of vision may be quite rapid.
Others - The commonest of these is retinal pigment epithelial detachments. The RPE is a layer under the retina and fluid may form under this pushing the retina forward. In some patients the problem may settle and the vision remain good but in most the vision eventually gets worse.
Why do people get macular degeneration?
- The exact cause is unknown.
- It is probably due to a combination of genetic and environmental factors.
- The commonest association of macular degeneration is with age.
- Recently there has been found to be a strong association with genetic changes.
- “Wet” macular degeneration is a bit more frequent in those who smoke, have blood pressure and are overweight.
- Diet may be important (see below).
Can macular degeneration be prevented? (or can I prevent it getting worse?)
You can’t change your genetic make-up or stop yourself getting older but there are some other things that may help.
Diet: There is evidence that having a diet rich in antioxidants and free radical scavengers such as Vitamin, C, E and zinc, and also containing the naturally occurring macular pigments lutein and zeaxanthin may help. These are found in green leafy vegetables such as spinach and yellow coloured foods such as sweet corn and yellow peppers.
Supplements: The Age Related Eye Disease Study (AREDS), showed benefit in reducing the risk of the development of advanced macular degeneration in patients at risk. That is those with “high” risk drusen (large drusen and retinal pigment alterations), or those who have already lost their vision in one eye due to macular degeneration. High doses were used: Vit C 500 mg; Vit E 400iu; beta-carotene 15 mg and Zinc 80 mg. Beta Carotene is not recommended in smokers. AREDS2 was published in May 2013, which found that beta-carotene may not be beneficial, nor was additional omega 3, but that additional lutein 10mg and zeaxanthine 2mg helped in some cases to slow progression. The additional benefit, above the original AREDS supplement, only applied to reducing the risk of progression to wet AMD not geographic atrophy. The benefits were less evident in those already on a healthy diet.
- Many supplements are available. Several supplements can be purchased with different doses of vitamins and antioxidants such as Viteyes advanced beta carotene free, Bausch and Lomb Preservision AREDS2 formular (available through Amazon) which seem to be the closest to the preferred supplement from the AREDS 2 study.
- Stopping smoking and having adequate blood pressure is strongly advised.
What treatment is available?
Eylea and lucentis are the main treatments now used. Both involve injections. They are given as injections into the eye as an outpatient. They are given via a very fine needle and are quick and relatively pain-free. We do not think fear of an injection should cause you not too have treatment as the results in terms of improvement of vision can be good. And the injection is not likely to be as bad as you think. These treatments are not a one off but rather a series of injections and follow up visits. Both involve giving three injections 4 weeks apart then further injections and follow up potentially for a few years. Eylea is currently being offered as a choice to new patients and may have the advantage of requiring two monthly visits rather than the one monthly required for lucentis, at least in the first year. Lucentis has been approved by NICE, Eylea has been approved in the northern region by the North East Advisory board, a decision by NICE is awaited.
Photodynamic therapy was previously our first line of treatment and still has a role in some cases. It involves injecting into a blood vessel in the arm a photosensitive dye called Visudyne™, which is taken up by the abnormal vessels. The dye is then activated by a low-powered laser, which stops the vessels causing further damage. The vessels can recur and repeat treatment may be required three monthly for a year or so.
Treatments require careful imaging of the eye. This usually involves fluorescein angiography at the beginning, which requires the injection of a dye in a blood vessel in the arm and repeat ocular coherence tomography (OCT).
There is no treatment possible for dry macular degeneration. The atrophic changes of the macula cannot be reversed or repaired. Supplements and dietary changes may help slow the process of dry ARMD down.
Surgery rarely can have a role in cases of sudden sub macular haemorrhage.
Active research into stem cells is being pursued but as yet has not led to retinal treatment for AMD.
Focal radiation has been promoted as a way of stabilising the eye and reducing the number of injections required but its true benefits are yet to be convincingly proven.
Magnifying intra-ocular lenses are promoted by some but would require very careful patient selection, are expensive and the true benefit is less clear.
What will happen if you are referred with possible macular degeneration?
Your vision and symptoms will be assessed.
- If the vision is already quite poor it may not help to have the treatment.
- If you do not have symptoms treatment may not be advised as treatment does require quite a lot of commitment involving regular visits to the hospital.
- Your eye will be examined and if appropriate, photographs of the eye will be taken.
- If it is thought treatment has a chance of helping an appointment will be made and further information on the specific treatment plan explained.
What will happen if no treatment is given?
If no treatment is given you will not lose your vision entirely as it is only the central vision that is affected. If it is the first eye that has been affected you are advised to return urgently if you notice a problem in the good eye, in particularly distortion and blurring of central vision.
Patients with poor vision can experience unusual, flashing or whirling lights. They may also report seeing shapes, animals or people that they know are not real. This is called Charles Bonnet Syndrome. It usually settles down over time without any intervention.
What extra help can be given?
Help can be given with low vision aids, such as magnifiers, and a clinic appointment can be arranged for their assessment. Registration of poor vision may provide extra help. A visual rehabilitation officer is available at the RVI- tel: 0191 282 0221.
There are many sources of patient information and some patient self-help groups such as the Macular Disease Society.