Researchers from the University of Miami, in collaboration with Johns Hopkins University, demonstrate that vision loss precedes a loss of mental capacity, suggesting that maintaining eye health could protect cognition in older adults. An estimated of 5.4 million US individuals, 71 years or older, have cognitive impairment without dementia. Cognitive impairment leads to a decreased quality of life, increased disability and dependency, increased health care costs and early mortality. A longitudinal study of 2,520 older US adults show that visual impairment with declining cognitive function indicate a stronger association with declining cognition than vice versa. Visual acuity (VA) was measured using Early Treatment Diabetic Retinopathy Study (ETDRS) charts, and cognitive status was assessed using the Mini-Mental State Examination (MMSE). A commentary states that “blindness and dementia have a substantial adverse effect on quality of life and social and economic activity, burden national and commercial health care budgets, and diminish daily experience for those affected.”
The results of a prospective longitudinal population-based study show that the mean (SD) age of patients was 73.5 (5.1) years, with the mean biannual decline of VA was 0.022 logMAR (approximately 1 line during 8 years; 95%CI, 0.018-0.026), and the mean biannual worsening of MMSE score was −0.59 (95%CI, −0.64 to −0.54; both P < .001). A worse baseline VA was associated with a worse baseline MMSE score (r = −0.226; 95%CI, −0.291 to −0.16; P < .001) while the rate of worsening VA was associated with the rate of declining MMSE score (r = −0.139; 95%CI, −0.261 to −0.017; P = .03). As highlighted by the results from JAMA Ophthalmology (2018;136(9):989-995), cross-lagged models indicated that VA in a previous assessment were associated with MMSE score in the subsequent round (β = −0.995, P < .001), and MMSE score in the previous round was associated with VA in the following round (β = −0.003, P < .001).
Research investigators state that, “understanding the cognitive changes that accompany aging and finding ways to slow down the pace of cognitive decline is critical for maintaining well-being in late life. The longitudinal association between vision and cognitive functioning suggests maintaining good vision may be an important interventional strategy for mitigating age-related cognitive changes.” Independent researchers show that “Health policy makers should note that eye care is not just about vision; it pays dividends over and above this by playing a crucial role in maintaining many aspects of health, economic activity, and quality of life throughout peoples’ lives.”