This article is more than 5 years old. Information may no longer be current.
Visual impairment directly and indirectly predicted mortality in older subjects
Arch Ophthalmol. 2009;127(10):1347-1353.
Click Here to Manage Email Alerts
Irreparable visual impairment in subjects younger than 75 years directly and indirectly predicted mortality, according to data from the Blue Mountains Eye Study.
"Disability in walking, which can substantially influence general health, represented a major indirect pathway," the study authors said.
The Blue Mountains Eye Study, conducted in Australia, included 3,654 adults age 49 years and older. Subjects were examined between 1992 and 1994, and again 5 and 10 years later. The Australian National Death Index provided data that confirmed participant deaths until 2005.
Investigators defined visual impairment as presenting, correctable and non-correctable, based on visual acuity in the better eye. They used Cox regression and structural equation modeling to draw associations between visual impairment and mortality risk.
Study results showed 1,273 participant deaths after 13 years. Data adjusted for mortality risk markers showed an association between higher mortality and non-correctable visual impairment. The association was more prominent among subjects younger than 75 years.
Analysis also showed that uncorrectable visual impairment bore a marked influence on mortality risk, with direct and indirect effects, in subjects younger than 75 years. Only disability in walking proved to be an indirect pathway for the link between visual impairment and mortality, the authors said.
This study confirms in an effective statistical manner what most of us have always suspected — that reduced vision is bad for one’s health and consequently is likely to shorten life expectancy. The adverse effect demonstrated in this regional population study is more pronounced in those under 75 years compared to older. Rather than using traditional statistical regression techniques which would underestimate the effect on mortality, structural equation modeling is employed, which permitted more complex relationships being included, resulting in giving a higher but more realistic estimate of the effect of visual impairment. This is done both directly and also enabling inclusion of other indirect means such as impairment of walking — a significant factor.
The study was from a large population based data set (3,654 people) with high participation rates and long follow up since commencing in 1992 continuing on to 2005, with 82% retention, giving substantiated power to the epidemiological study findings.
– Noel A. Alpins, FRACO, FRCOphth, FACS
OSN Refractive Surgery Board Member