Study associates visual impairment from AMD, cataract with increased mortality risk

Patients who are 49 years and older and have cataracts and those who are 49 to 74 years and have age-related macular degeneration appear to have higher mortality rates over an 11-year period compared with patients with neither ocular condition, according to a new analysis of data from the Blue Mountains Eye Study.

Sudha Cugati, MS, of the University of Sydney, Australia, and colleagues investigated the association between long-term mortality and visual impairment, cataract and AMD among 3,654 participants in the Blue Mountains Eye Study. All patients were 49 years or older when initially examined from 1992 to 1994, according to the study.

The researchers found that by Dec. 31, 2003 — an average of 11 years later — 1,051 participants (28.9%) had died.

Age-standardized mortality rates were higher among patients with any visual impairment than among those without. Specifically, patients with any visual impairment had a 54% mortality rate compared with a 34% rate for those without visual impairment. Patients with AMD had a 45.8% mortality rate vs. a 33.7% rate for those without AMD, and cataract patients had a 39.2% mortality rate vs. a 29.5% mortality rate for those without cataract, according to the study.

"After adjusting for factors that predict mortality, neither visual impairment nor [AMD] was significantly associated with all-cause mortality in all ages," the authors said. "Among persons younger than 75 years, however, [AMD] predicted higher all-cause mortality."

Among participants of all ages, having cataract also was associated with a higher risk of death from any cause, the authors noted.

However, it remains unclear whether there is a direct or indirect link between visual impairment and death or whether another factor not measured in the study affected the results, the authors noted.

"The implications of these findings also remain uncertain: whether such an association indicates that visual impairment, age-related eye disease or both are markers of aging and frailty or whether these ocular conditions accelerate aging, thus leading to relatively earlier death in older persons," they said.

"If a direct or indirect causal effect from visual impairment on earlier death is confirmed, regular assessment of vision in older persons may lead to early detection, facilitating treatments that could reduce the impact of visual impairment," they said.

The study is published in the July issue of Archives of Ophthalmology.