Visual impairment tied to death risk

Visual impairment (VI), particularly if non-correctable, seems to increase the risk of long-term mortality, a recent study has found.

Drawing from the 2003 Liwan Eye Study, researchers followed-up 1,399 participants after 10 years. VI was defined as an acuity of 20/40 or worse in the better-seeing eye. VI was deemed correctable only if subjective refraction could improve acuity to 20/40 or better.

At baseline, 22.9 percent (n=320) had VI. Compared with those who had no impairment, VI participants tended to be older, female, and more likely to have diabetes (p<0.05 for all). After a median follow-up of 9.38 years, 22.4 percent (n=314) of the participants had died.

Stratifying by baseline vision, researchers saw that mortality was significantly higher in those with vs without VI (40.0 percent vs 17.2 percent; log-rank p<0.05). Even after adjusting for age, sex, body mass index, diabetes and hypertension, family income, and education, Cox proportional hazards regression analysis confirmed that mortality risk was significantly elevated among participants with VI at baseline (hazard ratio [HR], 1.55, 95 percent confidence interval [CI], 1.14–2.11).

Further stratifications showed that the excess in mortality risk was driven by non-correctable VI, which increased the risk by nearly 200 percent (HR, 2.72, 95 percent CI, 1.86–3.98). Correctable VI, on the other hand, had no impact on 10-year mortality (HR, 0.99, 95 percent CI, 0.66–1.49).

“Our study found the significant association between VI and mortality, highlighting the importance of preventing and treating VI to prevent premature mortality. Further studies exploring the mechanisms underlying VI–mortality association are needed,” the researchers said.