The impact of visual impairment on health, function and mortality

Our aim was to determine the impact of visual impairment on self-rated health, function and mortality amongst a community-dwelling elderly cohort.

The study design was prospective and longitudinal, subjects being taken from an age-homogeneous, community-dwelling cohort comprising 452 subjects aged 70 in 1990 and 839 subjects aged 77 in 1998. Comprehensive data were collected by structured interviews and medical examinations carried out during home visits. Data included each subject's demographic and socio-economic profile, medical history, physical findings, functional status and self-rated health status. Visual acuity was measured using a Snellen chart and visual impairment was defined as best-eye corrected visual acuity of 20/40 or worse on Snellen chart testing.

Measured and self-reported visual impairment correlated closely, and were significantly more prevalent amongst subjects with low education and poor financial status. Visually impaired subjects showed significantly greater dependence in ADL and IADL, poor self-rated health, less ability to rely on friends, increased loneliness and, in men aged 77, increased visits to the emergency room and hospital admissions. Visual impairment at age 70 significantly predicted poor self-rated health (p=0.029, OR 2.36, 95% CI 1.09-5.10), dependence in ADL (p=0.007, OR 2.91, 95% CI 1.34-6.33), general tiredness (p=0.037, OR 2.40, 95% CI 1.06-5.44), and mortality, with a two-and-a-half-fold increase in risk of death at seven years (p=0.0017,OR 2.84, 95% CI 1.48-5.46).

Visual impairment in the elderly increases the risk of social, functional and medical decline.