November 15, 2021, 12:00 p.m. News Staff — On Oct. 26, the U.S. Preventive Services Task Force posted a pair of draft recommendation statements related to vision problems on its website for public comment.
Based on its review, the USPSTF concluded that the current evidence is insufficient to assess the balance of benefits and harms of screening for primary open-angle glaucoma in adults – an “I” recommendation that applies to adults age 40 years or older who present in primary care and do not have signs or symptoms of the condition.
The task force also concluded with an “I” grade that the current evidence is insufficient to assess the balance of benefits and harms of screening for impaired visual acuity in older adults. This recommendation applies to asymptomatic adults age 65 years and older who present without known impaired visual acuity and who are not seeking care for vision problems.
“Impaired vision and glaucoma are serious and common conditions that affect many people’s independence and quality of life,” said Katrina Donahue, M.D., M.P.H., a professor and vice chair of research in the Department of Family Medicine at the University of North Carolina at Chapel Hill and a member of the task force, in a press release. “Unfortunately, there is not enough evidence to determine if screening for these conditions in the primary care setting can help people who have not noticed problems with their vision.”
Glaucoma is the second leading cause of irreversible blindness in the United States and the leading cause of blindness in Black and Hispanic/Latino people. According to the National Eye Institute, open-angle glaucoma is the most common type of the condition in the United States, occurring in an estimated 90% of people with glaucoma.
Although glaucoma can affect anyone, those at increased risk include individuals older than 60 (especially individuals who are Hispanic or Latino); Black individuals older than 40; and those with a family history of the condition. About half of people with glaucoma do not know they have it, but early detection and treatment can often stop the damage and protect one’s vision.
Impaired visual acuity (defined by the task force as best corrected visual acuity worse than 20/40 but better than 20/200) refers to a decrease in the sharpness or clarity of vision, and is frequently associated with decreased quality of life in older individuals. The CDC’s Vision and Eye Health Surveillance System estimates that in 2017, the last year for which data are available, roughly 6 million Americans had some form of vision loss, with the condition more prevalent in women and in people 65 and older. VEHSS data also indicates a higher risk of vision loss in Hispanic/Latino and Black individuals than in white individuals.
“The task force is calling for more research to fully evaluate the benefits and harms of screening people for glaucoma and impaired vision in primary care who have not noticed any issues with their vision, especially those who are disproportionately affected,” remarked Carol Mangione, M.D., M.S.P.H., chair of the task force. “In the absence of evidence, clinicians should use their judgment when deciding whether to not to screen individual patients.”
When finalized, the recommendation statements will replace recommendations issued by the USPSTF on impaired visual acuity in 2016 and glaucoma in 2013.
The 2016 recommendation stated that there was insufficient evidence to assess the balance of benefits and harms of screening for visual acuity for the improvement of outcomes in older adults, while the 2013 recommendation stated that the evidence was insufficient to determine the balance of benefits and harms of screening for primary open-angle glaucoma in adults.
The AAFP supported both of the task force’s earlier recommendations.
To update these recommendations, the USPSTF commissioned a pair of reviews to evaluate the benefits and harms of screening for glaucoma in adults, and the benefits and harms of screening for impaired visual acuity in older adults.
For glaucoma, the task force stated that the review focused on screening for primary open-angle glaucoma; screening for and treatment of other types of glaucoma were outside the review’s scope.
For impaired visual acuity, the task force noted that the review focused on screening for impaired visual acuity associated with uncorrected refractive errors, cataracts and age-related macular degeneration, as well as the treatment of AMD. The task force also stated that the benefits and harms related to treatment of uncorrected refractive errors and cataracts has been previously established and, as such, was not addressed in the review.
Data sources for the evidence review on glaucoma screening consisted of studies from the Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews and the Medline database published through Feb. 9, 2021, as well as studies from previous reviews and reference lists. A total of 83 studies were included in the review, 67 of which were new.
The task force found that direct evidence on the benefits of glaucoma screening vs. no screening were limited. While screening tests such as optical coherence testing and visual field assessment were reasonably accurate in identifying individuals with open-angle glaucoma, screening showed no benefits on vision-related quality of life or function or increased risk of falls.
Topical medical treatments and surgical procedures such as laser trabeculoplasty for ocular hypertension or untreated open-angle glaucoma were associated with reductions in intraocular pressure and reduced risk of glaucoma progression based on visual field or optic nerve changes, but evidence on the association with visual outcome, quality of life and function was limited and indicated no clear effects.
Data sources for the evidence review on impaired visual acuity also included consisted of studies from the Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews and the Medline database published through Feb. 9, 2021, along with studies in the previous USPSTF report and reference lists. The evidence review included 25 studies, eight of which were new.
The evidence review found that compared with a complete ophthalmological examination, visual acuity tests had poor diagnostic accuracy for identifying visual conditions, with sensitivity ranging from 27% to 75% and specificity ranging from 51% to 87%. Evidence on the accuracy of other screening methods such as computerized screening tools and mobile applications was limited. In addition, screening questions were not accurate for identifying individuals at increased risk of impaired visual acuity due to uncorrected refractive errors, cataracts or AMD compared with a visual acuity eye chart.
With regard to early detection and treatment, results from four trials that compared screening vs. no screening, usual care or delayed screening found no differences in visual acuity or other clinical outcomes such as likelihood of vision disorders or vision-related functional impairment.
For wet AMD, results from four trials indicated that injections of vascular endothelial growth factor inhibitors were effective in improving visual acuity-related outcomes, including likelihood of visual acuity gain, reduced visual acuity loss and having vision of 20/200 or better, compared with placebo or no treatment.
For dry AMD, a systematic review of 19 trials found that antioxidant multivitamins were associated with decreased risk of progression to late AMD and more than three lines of visual acuity loss. Other evidence indicated that zinc was associated with a decreased risk of progression to late AMD. In addition, trial results showed that compared with placebo, the combination of antioxidants and zinc reduced the risk of progression to advanced AMD and visual acuity loss in patients with intermediate or advanced AMD in one eye.
Other potential therapies such as lutein and vitamin E showed no clear effects on AMD progression or visual acuity, and evidence on other health outcomes such as cognition and vision-related function and quality of life was limited.
No studies on the harms of screening for visual impairment in a primary care setting were available.
The task force is accepting public comments on the draft recommendation statement and draft evidence review on screening for glaucoma, and the draft recommendation statement and draft evidence review on screening for impaired visual acuity in older adults, until 11:59 p.m. ET Nov. 22.