Loss of vision associated with loss of cognition
Loss of vision may be associated with cognitive function impairment in older people, according to a study by researchers supported in part by NIA. The investigators sought to determine which factor—declining vision or cognitive function—contributed more to the association over time. They identified declining vision as having a greater association with cognitive deterioration than the reverse. Study results appeared in JAMA Ophthalmology online on June 28, 2018.
Visual impairment affects almost 3 million older adults in the United States. This can significantly affect physical and psychological health, resulting in reduced quality of life. The prevalence of blindness and visual impairment increases with age, particularly among people age 75 and older.
For this research, Diane Zheng of the University of Miami and colleagues analyzed data from the Salisbury Eye Evaluation Study, a longitudinal study that enrolled more than 2,500 participants aged 65 to 84 in the Salisbury area of Maryland. The study team used the Early Treatment Diabetic Retinopathy Study chart to measure visual acuity, or the ability to discern shapes and details of objects, and the Mini-Mental State Exam (MMSE) to measure cognitive function; participants were assessed in four rounds between 1993 and 2003.
The percent of participants with MMSE scores indicating cognitive impairment increased from 11 percent at baseline to 20.6 percent in the fourth round. Visual impairment was associated with poor cognitive function both cross-sectionally and longitudinally. Worsening vision had a stronger association with declining cognition than the reverse. The researchers note that maintaining good vision may be an important strategy for reducing age-related cognitive decline.
This research was funded in part by NIH grants K01AG052640, AG10184 and F31EY025936.
Reference: Zheng, D., et al. Longitudinal Associations Between Visual Impairment and Cognitive Functioning: The Salisbury Eye Evaluation Study, JAMA Ophthalmol. 2018 Sep 1;136(9):989-995. doi: 10.1001/jamaophthalmol.2018.2493