US Study Identifies Early Indicator of Age-Related Vision Decline Missed by Routine Eye Exams

Doha: A US study has found that contrast sensitivity testing could help detect age-related vision problems that are often missed during routine eye examinations, offering an earlier indicator of visual decline in older adults. According to Qatar News Agency, the study, conducted by researchers at the University of Michigan and published in JAMA Ophthalmology, found that difficulty reading more than six lines on a low-contrast eye chart with gradually fading letters may signal vision problems that conventional eye tests fail to detect. Unlike standard eye exams, which measure visual acuity using high-contrast black letters on a white background, contrast sensitivity testing assesses the eye's ability to distinguish objects from their background under lower-contrast conditions. Reduced contrast sensitivity has been linked to a higher risk of falls, driving difficulties, and loss of independence. "Traditional eye charts can miss important vision changes that often occur as we age," said Lindsey De Lott, a neu ro-ophthalmologist at the University of Michigan. She said low-contrast charts, in which letters gradually become lighter and harder to distinguish, can reveal vision problems that do not appear in conventional eye exams. De Lott said researchers had long recognized the importance of contrast sensitivity in assessing vision, but lacked a clinically meaningful threshold indicating when declining contrast sensitivity begins to affect everyday activities such as reading, recognizing faces, or watching television. The study analyzed data from 4,475 Medicare beneficiaries participating in the National Health and Aging Trends Study, and found that many older adults with normal visual acuity nonetheless had impaired contrast sensitivity and reported difficulties with daily tasks, including reading in dim light, distinguishing objects from their background, and navigating in low-light conditions. The researchers said adding contrast sensitivity testing to routine eye examinations for adults aged 65 and older could help identify treatable vision problems earlier, before they become apparent through standard visual acuity tests. They are now investigating whether reduced contrast sensitivity is associated with future declines in health and independence to improve prediction of age-related health risks.