Visual deterioration, mortality appear to be associated

The development of cataract and age-related macular degeneration (AMD) seems to be linked with increased mortality rates in older patients (aged 49 or more years), according to results of the Blue Mountains Eye Study. The finding confirms an association between visual deterioration and mortality found in other studies.

Key Points

Sydney, Australia-The development of cataract and age-related macular degeneration (AMD) seems to be linked with increased mortality rates in older patients (aged 49 or more years), according to the authors of a recent study. The finding confirms an association between visual deterioration and mortality found in other studies.

The investigators conducted a study in which they evaluated the association between visual impairment resulting from cataract, AMD, or other eye pathologies and long-term mortality. Between 1992 and 1994, 3,654 persons who were aged 49 or more years were examined as part of the Blue Mountains Eye Study. The investigators measured baseline visual acuity (VA); patients with best-corrected VA of 20/40 or less were considered visually impaired.

Mean follow-up

The mean follow-up period of the study sample was 11 years (median, 10.7 years; range, >1 to 12 years). The mortality rate during the 11 years was higher in visually impaired participants compared with those whose vision was unimpaired (75% versus 26.9%), according to study authors.

The authors found an association between visual impairment and decreased survival in an age- and sex-adjusted model (hazard ratio [HR], 1.4; 95% confidence interval [CI], 1.1 to 1.7), but this association weakened to become borderline non-significant after further adjustment for other factors significantly associated with poor survival (HR, 1.3; 95% CI, 0.98 to 1.7). Among persons who were aged fewer than 75 years at baseline, however, visual impairment predicted higher all-cause mortality (HR, 2.9; 95% CI, 1.6 to 5.5).

Researchers found that the association continued in patients aged fewer than 75 years but lessened after additional adjustment for triglyceride level, fibrinogen level, educational level, and walking disability (HR, 1.97; 95% CI, 0.8 to 4.8).

Results also indicated that the cumulative 11-year mortality rate was higher in those who had AMD compared with those who did not (55.8% versus 25.9%, respectively). In patients of all ages, the investigators found no significant difference in all-cause mortality risk between those with AMD and those without AMD (HR, 1.0; 95% CI, 0.8 to 1.3).

In study participants aged fewer than 75 years, however, the existence of any AMD predicted higher all-cause mortality (HR, 1.7; 95% CI, 1.2 to 2.5).

"It is conceivable that long-term (11-year) mortality in people who were over age 75 years at the baseline examinations would predominantly be driven by other aging processes," they wrote.