LIFESTYLE CHOICES

A new report from the Beaver Dam Eye Study (BDES) provides evidence that reinforces existing messages about lifestyle choices for preserving ocular and general health. The research, which was published recently in the journal Ophthalmology (Vol. 104, Issue 11), examined associations between smoking, alcohol consumption and physical activity and the development of visual impairment.

“The BDES and other epidemiological studies found relationships between these modifiable lifestyle factors and specific age-related eye diseases. We thought it would be of interest to quantitate the effect of these behaviours on a functional outcome associated with those diseases,” explained Ronald Klein MD, MPH, lead author, and professor of ophthalmology and visual sciences, University of Wisconsin School of Medicine and Public Health, Madison.

In the cohort of nearly 5,000 patients followed for up to 20 years, the cumulative incidence of visual impairment was 5.4 per cent. Results from the final multivariate adjusted model found that being physically active and having an occasional drink significantly reduced the odds of becoming visually impaired. Persons with a physically active lifestyle had a 60 per cent lower risk of developing visual impairment compared to their “sedentary” counterparts who engaged in regular activity less often. Those reporting not drinking alcoholic beverages in the past year were about twice as likely to become visually impaired than occasional drinkers (persons having less than one alcoholic beverage per week).

Although there was also about a two-fold higher risk of incident visual impairment among current smokers compared to never smokers, the difference was not significant. However, current and past smokers had greater loss in the number of letters read correctly during follow-up than never smokers.

UNMEASURED VARIABLES
Commenting on the results to EuroTimes, Dr Klein noted that these epidemiological data do not establish causality and it is possible that the lifestyle factors are markers of unmeasured variables. “In particular, dietary factors that are thought to be protective against AMD development were not considered in the analyses,” he said. “However, ophthalmologists should tell their patients about our findings on vision. In addition, they should be telling all patients not to smoke for general health reasons and patients at risk of AMD not to smoke because of evidence that smoking increases their risk.”

He noted ophthalmologists should be careful to acknowledge there is little evidence that stopping smoking, drinking an occasional alcoholic beverage and becoming physically active will prevent visual loss. “However, physicians are already warning patients not to smoke, to engage in physical activity and unless there are contraindications, to consider one to two drinks per week because these behaviours have been found to protect against cardiovascular disease,” Dr Klein observed.