For seniors, maintaining good vision may be an important step in putting the brakes on age-related cognitive decline, a recent study finds.

Since worsening vision and declining cognitive function are common in older people, a team of Maryland researchers investigated the association between the two. This prospective longitudinal population-based study included 2,520 adults ages 65 to 84 who were first assessed between 1993 and 1995, with subsequent assessments two (round two), six (round three) and eight (round four) years later. Researchers measured visual acuity (VA) by Early Treatment Diabetic Retinopathy Study charts and cognitive status through a Mini-Mental State Examination (MMSE).

The average participant’s age was 73.5. Enrollment declined with each round of testing; by year eight, the study had 1,250 participants. Researchers noted more than half of the participants died during the course of the study, which factored into the diminished enrollment.

Researchers reported the average decline of visual testing was one line. The mean biennial worsening of the cognitive score was -0.59, and the worse baseline VA was associated with worse baseline cognitive scores. The rate of worsening vision was also associated with the rate of declining cognitive scores. The investigators noted VA in the previous round was associated with the cognitive score in the subsequent round. Likewise, cognitive scoring in the previous round was associated with VA in the following round. However, the standardized effect size of VA on the cognitive score was larger relative to the reverse effect, which researchers believed show VA was likely the driving force behind the associations.

“Worsening vision in older adults may be adversely associated with future cognitive functioning. Maintaining good vision may be an important interventional strategy for mitigating age-related cognitive declines,” researchers said.

Zheng DD, Swenor BK, Christ SL. Longitudinal associations between visual impairment and cognitive functioning: the Salisbury eye evaluation study. JAMA Ophthalmol. June 28, 2018. [Epub ahead of print].