28,000 Cases of age related macular degeneration causing visual loss in people aged 75 years and above in the United Kingdom may be attributable to smoking.
BACKGROUND
Age related macular degeneration (AMD) causing visual impairment is common in older people. Previous studies have identified smoking as a risk factor for AMD. However, there is limited information for the older population in Britain.


METHODS
Population based cross sectional analytical study based in 49 practices selected to be representative of the population of Britain. Cases were people aged 75 years and above who were visually impaired (binocular acuity <6/18) as a result of AMD. Controls were people with normal vision (6/6 or better). Smoking history was ascertained using an interviewer administered questionnaire.


RESULTS
After controlling for potentially confounding factors, current smokers were twice as likely to have AMD compared to non-smokers (odds ratio 2.15, 95% CI 1.42 to 3.26). Ex-smokers were at intermediate risk (odds ratio 1.13, 0.86 to 1.47). People who stopped smoking more than 20 years previously were not at increased risk of AMD causing visual loss. Approximately 28,000 cases of AMD in older people in the United Kingdom may be attributable to smoking.


CONCLUSIONS
This is the largest study of the association of smoking and AMD in the British population. Smoking is associated with a twofold increased risk of developing AMD. An increased risk of AMD, which is the most commonly occurring cause of blindness in the United Kingdom, is yet another reason for people to stop smoking and governments to develop public health campaigns against this hazard.
Evans
J R
JR
International Centre for Eye Health, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK. Jennifer.evans@lshtm.ac.uk
Fletcher
A E
AE
Wormald
R P L
RP
D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008268:Macular Degeneration / Q000453:epidemiology / Q000209:etiology*; D008297:Male; D012044:Regression Analysis; D012307:Risk Factors; D017678:Sex Distribution; D012907:Smoking / Q000009:adverse effects*; D006113:United Kingdom / Q000453:epidemiology