From the Guidelines
Age significantly impacts the reliability of visual acuity (VA) testing and Spot vision screening performance, particularly in older adults, where the prevalence of vision impairment increases with age, ranging from 1% in persons aged 65 to 69 years to 17% in persons older than 80 years. This is due to various factors, including the presence of comorbid conditions such as cognitive impairment, which may lead to underreporting of vision impairment, as well as common age-related conditions like cataracts, age-related macular degeneration (AMD), and uncorrected refractive errors that can interfere with both traditional VA testing and automated screening devices 1. Some key points to consider include:
- The prevalence of vision impairment increases with age, with an estimated 1.8 million older adults in the United States being visually impaired in 2000 1.
- Uncorrected refractive errors, cataracts, and AMD are the most common causes of vision impairment in older adults, with refractive errors affecting an estimated 6.7 million adults older than 65 years in the United States in 2000 1.
- The US Preventive Services Task Force (USPSTF) recommends routine vision screening with the Snellen visual acuity test for elderly persons, as it readily identifies impaired visual acuity and refractive errors are correctable 1.
- Clinicians should consider using age-appropriate testing methods, allowing extra time, and potentially performing multiple measurements to ensure accurate assessment of visual function in older adults. Given the potential for decreased functional capacity and quality of life associated with vision impairment in older adults, it is essential to prioritize reliable VA testing and Spot vision screening performance in this population, taking into account the potential challenges and limitations associated with age-related conditions and cognitive impairment.
From the Research
Age Impact on VA Testing and Spot Performance
- The reliability of VA testing and spot performance can be impacted by age, with older adults potentially showing practice effects and improved performance over time 2.
- A study on repeated computerized cognitive testing in healthy older adults found that reaction times on tasks such as inhibition, response switching, and working memory typically showed practice effects, which were most prominent between the first two time points 2.
- However, the same study found that most reaction time tasks investigated showed moderate to good test-retest reliability, although longer familiarization periods may be warranted to reduce practice effects and improve initial reliability 2.
- In terms of visual acuity, a study on the association of VA improvement with uncorrected refractive error in patients new to low vision clinics found that at least 2-line VA improvement was more likely to be seen in patients aged 40 to <65 years compared to those aged 20 to <40 years 3.
- The study also found that African American patients and those with moderate vision impairment were more likely to experience VA improvement 3.
- Another study on the development and validation of a brief web-based measure of cognition for older adults found that the Survey for Memory, Attention, and Reaction Time (SMART) had fair to excellent test-retest reliability, and that total SMART completion time was significantly related to global cognition 4.
- A practical guide for clinicians on low vision services notes that low vision is most commonly caused by age-related macular degeneration, glaucoma, and diabetic retinopathy, and that most patients with low vision are elderly 5.
- A study on on-road driving test performance in veterans found that age was not associated with failure rates, but that poorer processing speed and selective/divided attention were associated with higher failure rates 6.