Articles about Eye Health and Disease from 2005


Smoking and Age-related Macular Degeneration: A Medical Literature Review of the Association Smoking and AMD


(From J Thornton, et al, Eye 2005 19, 935−944)


Age-related macular degeneration (AMD) is a leading cause of severe and irreversible vision loss in the Western world. As there is no effective treatment for all types of AMD, identifying modifiable risk factors (risk that can be altered by a change in behavior) is of great importance. This review evaluates the epidemiological evidence associating smoking with AMD.

In general, age has been found the most important, but clearly non-modifiable, risk factor for AMD. A positive family history of AMD, is associated with a high risk of the disease, but this is also a non-modifiable risk factor.  As a modifiable risk factor, low dietary intake or low plasma concentrations of antioxidants may be associated with AMD.

Systematic review of published epidemiological studies were evaluated against established criteria for evidence of a causal relationship.  In total, 17 studies (cross-sectional studies, prospective cohort studies, and case−control studies) were included in the review.  The age range for subjects in most studies was 40−80 years. Approximately equal numbers of males and females were included in studies where data was available.  Most studies originated from North America (eight studies), Europe (five studies) or Australia (two studies).

A total of 13 studies found a statistically significant association between smoking and AMD with increased risk of AMD of two- to three-fold in current-smokers compared with never-smokers. Five studies found no association between smoking and AMD. There was also evidence of dose-response with the risk of developing AMD increasing as the intensity of smoking increases. There was evidence of a temporal (time related) relationship of smoking on AMD, and a reversibility of effect, with evidence that ex-smokers had a lower risk of AMD, suggesting this reversibility.

It was noted that although the review provided strong evidence for an AMD link with active smoking, the evidence for passive smoking increasing AMD risk is sparse

The authors concluded that the medical literature review confirmed a strong association between current smoking and AMD, which fulfilled established causality criteria. Cigarette smoking is likely to have toxic effects on the retina. In spite of the strength of this evidence, there appears to be a lack of awareness about the risks of developing eye disease from smoking among both healthcare professionals and the general public.





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