Level III Services: Preventive services that clinicians and care systems could provide to patients, but only after careful consideration of the costs and benefits. Providing these services is left to the judgment of individual care systems, clinicians and their patients.
|The USPSTF recommendations are fully endorsed by the ICSI Preventive Services work group.
||Grade of Recommendation and Level of Certainty as Evaluated by USPSTF|
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Level of Certainty:
There is limited direct evidence on the effectiveness of screening for visual impairment in the primary care setting. Three fair-quality cluster randomized, controlled trials found no difference with respect to vision and other clinical or functional outcomes between vision screening (as part of a multi-component screening) with visual acuity testing or questions compared with usual care, no vision screening or delayed screening. The application of this evidence to screening in a primary care setting has limitations. Issues with the study methods include failure to report allocation concealment, lack of intention-to-treat analysis and unclear blinding. Other limitations to the applicability of this evidence to the primary care setting include the fact that the recommended interventions are provided by eye care specialists and that many patients do not get the recommended glasses.
Consistent evidence shows that older adults with refractive errors could achieve visual acuity better than 20/40 with refractive correction. Evidence from a few trials indicates that immediate correction of refractive error with eyeglasses in older adults is associated with improved short-term, vision-related quality of life or function compared with delayed treatment. A systematic review of 179 randomized, controlled trials and observational studies found refractive surgery to be highly effective at improving refractive errors, with 92 to 94% of persons with myopia and 86 to 96% of persons with hyperopia achieving visual acuity of 20/40 or better. However, most of these studies were done in younger adults, limiting generalizability to older adults.
Cataract surgery is consistently associated with improved visual acuity in observational studies: Approximately 90% of patients have postoperative visual acuity greater than 20/40. Results from studies in adults older than age 85 years are mixed. The best evidence suggests that most adults older than age 85 years also benefit. Although the proportion is smaller than in younger adults, more than three-quarters still seem to benefit. Evidence shows that cataract surgery improves vision-related quality of life and function, but evidence from observational studies on effects on motor vehicle accidents and death is sparse and inconclusive: one study reported fewer motor vehicle accidents with cataract surgery, and one study reported increased risk for death in patients who do not have cataract surgery. No randomized trials were identified that evaluated clinical outcomes associated with cataract surgery versus no surgery. Evidence on the effect of cataract surgery on the risk for falls and fractures is limited and inconsistent.
A systematic review reported that antioxidants were effective for slowing the progression of dry AMD, but conclusions are primarily based on 1 large, good-quality trial – the Age-Related Eye Disease Study. The systematic review found that a multivitamin (composed of vitamins C and E and β-carotene with the addition of zinc) was associated with reduced likelihood of progression to advanced AMD (adjusted odds ratio, 0.68); however, the differences in the likelihood of losing measurable visual acuity did not reach statistical significance. For wet AMD, laser photocoagulation seems to be superior to no treatment for progression of vision loss (loss of ≥ 6 lines of visual acuity) after two years (relative risk, 0.67), although the quality of the trials evaluating this therapy is limited. Two good-quality systematic reviews of photodynamic therapy found verteporfin to be superior to placebo for preventing loss of visual acuity; quality-of-life outcomes were not reported from the trials. Injections with the vascular endothelial growth factor inhibitors pegaptanib and ranibizumab are effective for reducing the risk for visual acuity loss and blindness, but evidence on vision-related functional outcomes is mixed.
No evidence was found of serious harms from visual screening of asymptomatic older adults. Data on harms of treatment of refractive error in older adults are limited. One fair-quality trial found that vision screening by an optometrist in frail, older adults (n = 309) was associated with an increased risk for falls (rate ratio, 1.57 [95% CI, 1.20 to 2.05]; P = 0.01). Approximately one-half of the participants were prescribed new eyeglasses or were referred for further treatment. A small observational study reported an association between multifocal lens use and increased risk for falls in older adults. Serious harms, including vision loss, are rare as a result of contact lens use or refractive surgery. Corneal ectasia, a known harm of refractive surgery, occurs at a median rate of 0.2%. Cataract surgery can lead to posterior capsule opacification of the implanted lens, requiring an external laser procedure; reported rates of this complication vary widely from 0.7% to 48%. More recent studies report an incidence of 28% at five years. Endophthalmitis, bullous keratopathy, dislocation of the intraocular lens, macular edema and retinal detachment are other complications associated with cataract surgery.
Pooled data from trials of antioxidant vitamins and minerals reported no association with withdrawal due to gastrointestinal symptoms. The largest trial reported an increased risk for hospitalizations due to genitourinary causes with zinc and an increased risk for yellow skin with antioxidants; no association with increased hospitalizations, death or lung cancer was found.
Laser photocoagulation for wet AMD is associated with an increased risk for acute visual acuity loss (3 months after the procedure) but, as described earlier, is associated with a reduced risk for visual acuity loss at two years. Verteporfin carries an initial risk for acute visual acuity loss and a greater risk for back pain related to the infusion. Harms associated with intravitreal injections of vascular endothelial growth factor inhibitors include endophthalmitis, uveitis, increased intraocular pressure, traumatic cataract and retinal detachment; studies report no associations with hypertension or thromboembolic events.
In the highest-quality trial, universal vision screening identified about 10 times more patients with vision impairment and correctable vision impairment than targeted screening, yet found no difference in the rate of visual acuity worse than 20/60 after 3- to 5-year follow-up. As in the previous USPSTF evidence synthesis, no direct evidence indicates that screening for vision impairment in older adults in primary care settings is associated with improved clinical outcomes. Limited data from one trial reported that vision screening by an optometrist may be associated with an increased risk for falls, possibly because of the need to adjust to the vision correction or increased activities that may predispose to falls.
Although visual acuity testing is adequate for identifying refractive errors, it might be inadequate for identifying early AMD or early cataracts. Effective treatments are available for uncorrected refractive error, cataracts and AMD. Overall harms seem to be small; however, many of the treatments carry a small risk for serious complications, including acute visual loss.
Although treatments that entail little harm can correct impaired visual acuity, limited evidence is available on the effect of screening and treatment on quality of life, overall functioning and vision-related functioning, especially in older adults without self-perceived visual problems. This lack of evidence prevents the USPSTF from assessing the magnitude of net benefit for screening for visual acuity impairment.”