Health news - Smoking doubles the risk of blindness
16 September 2005 - written by Zosia Kmietowicz for Bupa's health information team
Smokers are twice as likely to lose their sight compared with non-smokers as they grow older.1
There is a proven link between smoking and age-related macular degeneration (AMD), which is the leading cause of sight loss in older people. Yet most smokers have no idea that their habit could affect their eyes according to the results of the recently released AMD Alliance International Survey 2005.2
How was the study carried out?
Researchers interviewed 1023 people in the UK by telephone. They were asked if they smoked; nearly one third said they did. They were also asked how much they knew about age-related macular degeneration (AMD).2
Those that knew something about AMD were asked to name the part of the body they thought was affected by it. They were given a list of organs to choose from. Interviewees were also asked what they thought were the main risk factors for AMD.2
What were the findings?
- Only seven percent of people knew that AMD affects the eyes.2
- Only 4 out of 10 people knew that smoking was the main risk factor for AMD.2
- Seven out of 10 smokers said they would quit or cut down if they knew that smoking increased the risk of going blind.2
What is the increased risk of blindness if you smoke?
People who smoke may be twice as likely to develop AMD, and risk blindness, compared with those who have never smoked.1 Some studies put smokers' risk at three to four times that of non-smokers.2,3
What is AMD?
The macula is a small, but crucial, area of the retina at the back of your eye. Cells in the macula are important for clear central vision, as well as distinguishing colours. You use them when you read, drive, watch TV, use a computer and sew, for example.2
In AMD, the cells in the macula gradually deteriorate so that they are no longer able to do their job properly. One eye tends to be affected first, but the other eye often becomes damaged sometime later. The main symptoms are blurred or distorted vision.2 Often there are no symptoms in the early stages of AMD.
There are two types of AMD - dry AMD and wet AMD.2
What is the difference between dry AMD and wet AMD?
Dry AMD is the most common form. It takes several years for the macula to become so badly damaged that sight is affected. There is no treatment for this type of AMD.2
Wet AMD is much less common, but it tends to progress more quickly. People can start to lose their sight in just a few months. Wet AMD occurs when new blood vessels form behind the macula. The blood vessels leak into the eye causing damage to the macula. If it's diagnosed early, some treatments can help to slow down or stop this damage.2
The exact reason why the cells of the macula are damaged in AMD is not known.
Who is affected?
As its name suggests, older people are most at risk of AMD. It generally affects people over 50. Approximately 1 in 10 people aged 55 to 64 is affected. This rises to nearly 2 in 10 people aged 65 to 74, and 3 in 10 people over 74.1 Out of those affected, approximately 8 in 100 people over 75 will have some degree of blindness.2
How many people suffer from AMD in the UK?
Every week 300 people in the UK lose their sight because of AMD.4 Altogether an estimated 500,000 people in the UK have the condition.4
What are the other main risk factors?
As well as smoking, having a history of AMD in your family increases your risk of AMD. Other risk factors include:2
- having low levels of certain nutrients
- being obese
- having high blood pressure
- eating a diet high in fat (especially saturated and mono-unsaturated fats)
Why does smoking increase the risk?
No one knows for certain but there are several theories. Researchers think that certain chemicals in cigarette smoke might disrupt blood flow to the retina, resulting in damage. These chemicals may also alter nutrients in the blood called antioxidants, which are thought to protect the macula against damage.5
Does the risk lessen if you quit smoking? How long after?
Stopping smoking does reduce the risk of developing AMD, but it may take as long as 15 or 20 years of not smoking before an ex-smoker's risk drops to the level of someone who had never smoked.5
What do the researchers advise?
The researchers say that the most important thing you can do to protect yourself against AMD is not to smoke, and if you do smoke, to stop.2 However, they admit that quitting can be difficult and advise people who want to stop smoking to see a professional who can help them.
There are a number of other things you can do to reduce your risk of AMD.2
- Eat a diet that is low in fat and includes lots of leafy green vegetables, nuts and fish.
- Watch your weight, blood pressure and cholesterol levels.
- If a close relative has AMD, have your eyes checked by an eye-care professional. This should include a test which involves looking at the retina.
Bupa Information
Further information
- Giving up smoking
0800 169 0 169
www.givingupsmoking.co.uk - Macular Disease Society
0845 241 2041
www.maculardisease.org - Royal National Institute of the Blind
0207 3912082
www.rnib.org.uk
References
- Evans JR, Fletcher AE, Wormwald RPL. 28,000 cases of age related macular degeneration causing visual loss in people aged 76 years and above in the United Kingdom may be attributable to smoking. Br J Ophthalmol 2005; 89: 550-553.
- Awareness of Age-related Macular Degeneration and Associated Risk Factors. AMD Alliance International: Campaign Report 2005.
www.amdalliance.org - Kelly SP. Smoking and blindness (Editorial). BMJ 2004; 328: 537-538.
- A vital eye test could save your sight. Age Concern.
www.ageconcern.org.uk - Christen WG, Glynn RJ, Manson JE, Ajani UA, Buring JE. A prospective study of cigarette smoking and risk of age-related macular degeneration in men. JAMA. 1996;276:1147-1151.
All pages were accessed on 12/09/05
