A disease that affects nearly 15% of the population yet little is known of the cause, Fergus Bescoby takes a look at age-related macular degeneration (ARMD)
There are many types of macular disease, the most common of which is age-related macular degeneration (ARMD).
Macular degeneration (MD) is the collective term for over 1,500 conditions which affect central vision through damage to the macula. It is estimated that there are over 500,000 people with macular conditions in the UK. Macular degeneration is the most common form of visual impairment in the UK and throughout the developed world.
The effects of macular degeneration have a major impact on the life of the affected individual who cannot drive or carry out ordinary everyday tasks. For younger people with macular degeneration who are of working age, the impact on their ability to work is very profound.
What is ARMD?
ARMD is a disorder leading to the loss of central vision (the ability to see straight ahead). It is the most common cause of vision loss in people over sixty. By the age of seventy-five, it is thought that nearly 15% of people are affected. Macular degeneration does not lead to total blindness as it only affects central and not peripheral vision.
ARMD occurs when there is damage to the cells of the macula (the central part of the retina). Light enters the eye through the pupil and is focused on the retina which then sends the messages it receives to the brain. The macula is a small area in the centre of the retina that is responsible for sharp, detailed central vision. ARMD results in a gradual distortion of central vision, and sometimes leads to a central blind spot called a scotoma. When central vision is impaired, a person may have difficulty recognising faces and colours, driving a car, reading print, or doing close handwork such as sewing or other handcrafts.
In the centre of the retina is an area called the macula. The function of the macula is to allow people to see straight ahead. When there is damage to the cells of the macula, this ability is impaired and people cannot see the fine detail required for reading, writing and colour perception.
Normally, both eyes are affected by ARMD but a diagnosis may be delayed by only one eye being affected before the other and the loss of central vision not being so obvious.
There are two main types of ARMD: 'wet' and 'dry'. They can be detected by an optometrist but are not perceived as wetness or dryness by an affected individual.
The wet form of ARMD in its advanced stages causes rapid growth of small blood vessels beneath the retina. Affected blood vessels leak blood and other fluid, forming scar tissue that causes vision loss.
Dry ARMD is the more common form and is less severe. It is caused by the deterioration of the tissue of the macula. Yellowish deposits called drusen form under the macula, causing it to thin and dry out.
What causes ARMD?
At the moment, the exact cause for ARMD is not known. However, a number of risk factors have been identified.
- Age - ARMD is an age-related condition so growing older makes it more likely.
- Gender - Women seem more likely to develop macular degeneration than men.
- Genetics - There appear to be a number of genes which can be passed through families which may have an impact on whether someone develops ARMD or not.
- Smoking - Smoking has been linked by a number of studies to the development of ARMD. It has also been shown that stopping smoking can reduce the risk of ARMD developing.
- Sunlight - Some research suggests that lifetime exposure to sunlight may affect the retina. It is a good idea to wear sunglasses to protect the eyes.
- Nutrition - Research suggests some vitamins and minerals can help protect against ARMD.
Although nothing can be done about age, gender and the genes we inherit, it is possible to control the environmental factors that seem to be linked to ARMD. Protecting your eyes from the sun, eating a well balanced diet with plenty of fresh fruit and vegetables and stopping smoking may all help to delay the progress of ARMD.
Possible treatment
While there is no cure or reliable therapy for dry macular degeneration, there are approved treatments for some people with wet macular degeneration. These may involve various types of laser, one of which, used in photodynamic therapy (PDT), combines the injection of Visudyne with cold laser treatment. Others include surgical operations on the macula and injections into the eye of substances which can halt the progress of scar formation.
Optometrists, GPs and ophthalmic specialists can advise on ways to maximise the visual abilities of affected people. Among the ways of doing this is effective use of peripheral vision and the use of vision aids such as magnifiers.
Underwriting Implications
- Life Cover. Will normally be accepted at Standard Rates unless there is a more sinister underlying cause for the loss of vision.
- Disability/IP. An exclusion will generally be applied (Any disease or disorder of either eye including blindness).
-Critical Illness (CI) cover/Serious Illness (SI). Cover for blindness or loss of vision will normally be excluded from the benefit.
At claim stage
Generally speaking under disability and CIC/SIC policies, the majority of companies will only pay out on total and permanent irreversible blindness and as discussed earlier, ARMD will normally not lead to this. Companies offering severity-based CIC/SIC products however will offer some form of payment for slightly less disabling conditions, such as central blindness or blindness in one eye.
- Fergus Bescoby is underwriting manager at PruProtect
Sources: The Macular Disease Society (MDS), Hannover Re www.cafamily.org.uk
ARMD at a glance
ARMD is the leading cause of low vision among older people and occurs most frequently among Caucasians.
It attacks and weakens the central portion of the eye (the macula) responsible for central vision and essential for making out detail.
Results in blurred vision in the center of the eye and can also cause blind spots in your centre of vision.
It is a very serious condition but does not result in total blindness. In fact, with the help of a vision loss specialist, you can learn to use your side vision to read and perform other tasks usually performed by the central part of the eye.
What are the signs?
The first signs of loss of central vision can include:
- Distorted or blurred objects;
- Shape and size distortion of objects;
- Undulating or fuzzy straight lines;
- Light sensitivity;
- Perception of non-existent lights and shapes;
- Straight lines appear wavy;
- Dark spaces in your centre of vision.
