Visual impairment and mortality: are they related?

In this issue of the Journal of the Chinese Medical Association, we have included an article from the Shihpai Eye Study. Therein, Kuang et al reported the relationship between visual impairment and 3-year mortality among older people in the Shihpai area in the city of Taipei. The association between visual impairment and mortality has been extensively studied over a lengthy period of time. The Beaver Dam Eye Study at Beaver Dam, WI, USA reported that poorer survival was associated with more severe cataracts and visual impairment in 1995. A later follow-up study showed that cataracts, diabetic retinopathy, and visual impairment were associated with poorer survival during a 14-year period in 2006. The Salisbury Eye Evaluation Project in Salisbury, MD, USA described how worse baseline acuity was associated with a higher mortality rate in a prospective 8-year cohort in 2005. They reported a similar association in 2014, and also observed that a decline in visual acuity over time was associated with increased mortality risk. The Blue Mountains Eye Study in Sydney, Australia reported that age-related cataracts and visual impairment were associated with increased mortality in older people in 2001, and then described the association between cataracts and age-related macular degeneration with higher mortality rate, although the association with visual impairment could not be verified in 2007. In 2009, they reported that visual impairment predicted mortality in a 13year period. These long-term epidemiological studies have shown an association between visual impairment and increased mortality, with a variety of possible mechanisms.