Screening for Impaired Visual Acuity in Older Adults: Updated Evidence Report and Systematic Review for the US Preventive Services Task Force

Importance  Impaired visual acuity is common among older adults and can adversely affect function and quality of life.

Objective  To update a 2009 systematic review on screening for impaired visual acuity among older adults for the US Preventive Services Task Force (USPSTF).

Data Sources  Ovid MEDLINE (2008 to January 2016), Cochrane Central Register of Controlled Trials, and Cochrane Database of Systematic Reviews.

Study Selection  Randomized clinical trials of screening; diagnostic accuracy studies of screening tests in primary care settings; and randomized clinical trials of treatment vs placebo or no treatment for uncorrected refractive errors, cataracts, and dry (atrophic) or wet (exudative) age-related macular degeneration (AMD). Studies of screening and diagnostic accuracy were limited to asymptomatic adults 65 years or older; studies of treatment included asymptomatic adults of any age.

Data Extraction and Synthesis  One investigator abstracted data, a second checked data for accuracy, and 2 investigators independently assessed study quality using predefined criteria. Random-effects meta-analysis was used to estimate the relative and absolute benefits of vascular endothelial growth factor inhibitors (anti-VEGF) for wet AMD.

Main Outcomes and Measures  Visual acuity, vision-related function, functional capacity, harms, and diagnostic accuracy.

Results  Three trials (n = 4728) from the 2009 USPSTF review found that screening for impaired visual acuity was not associated with improved visual or clinical outcomes. In 1 good-quality trial (n = 3346), universal screening identified 27% of persons with impaired visual acuity and correctable impairment vs 3.1% with targeted screening, but there was no difference in the likelihood of visual acuity worse than 20/60 after 3 to 5 years (37% vs 35%; relative risk [RR], 1.07; 95% CI, 0.84-1.36). The 2009 review found that effective treatments are available for uncorrected refractive errors and cataracts. Ten-year trial results of dry AMD found an antioxidant/zinc combination was associated with decreased risk of visual acuity loss (46% vs 54%; odds ratio, 0.71; 95% CI, 0.57-0.88). An updated meta-analysis found anti-VEGF for wet AMD was associated with greater likelihood of having vision 20/200 or better vs sham injection (4 trials; RR, 1.47; 95% CI, 1.30-1.66; I² = 42%; absolute risk difference, 24%; 95% CI, 12%-37% after 1 year). New evidence on the diagnostic accuracy of visual acuity screening tests was limited and consistent with previous findings that screening questions or a visual acuity test was associated with suboptimal accuracy.

Conclusions and Relevance  Screening can identify persons with impaired visual acuity, and effective treatments are available for common causes of impaired visual acuity, such as uncorrected refractive error, cataracts, and dry or wet AMD. However, direct evidence found no significant difference between vision screening in older adults in primary care settings vs no screening for improving visual acuity or other clinical outcomes.

Quiz Ref IDImpaired visual acuity refers to decreased clarity or sharpness of vision. Impaired visual acuity is associated with decreased function and quality of life and increased risk of falls and other accidental injuries.^1-5 The prevalence of impaired visual acuity increases with age.^6,7 Impaired visual acuity may be unreported or unrecognized in older persons because vision changes can be relatively subtle, progress slowly over time, or occur in persons with cognitive impairment.

The US Preventive Services Task Force (USPSTF) commissioned this review to update a 2009 review^8,9 and Recommendation Statement¹⁰ on screening for impaired visual acuity due to uncorrected refractive errors, cataracts, and dry (atrophic) or wet (exudative) age-related macular degeneration (AMD). The USPSTF previously concluded that the evidence was insufficient to assess the balance of benefits and harms of screening for visual acuity for the improvement of outcomes in older adults (I statement).

Using established methods,¹¹ the USPSTF determined the scope and key questions for this review. The final research plan was posted on the USPSTF website (http://www.uspreventiveservicestaskforce.org/Page/Document/final-research-plan93/impaired-visual-acuity-in-older-adults-screening) prior to conducting the review. The analytic framework and key questions (KQs) used to guide the review are shown in Figure 1.

Detailed methods and data for this review are contained in the full USPSTF review¹² (http://www.uspreventiveservicestaskforce.org/Page/Document/final-evidence-review147/impaired-visual-acuity-in-older-adults-screening), including search strategies, inclusion criteria, and abstraction tables; the full review also includes evidence on effectiveness of older treatments for wet AMD (laser photocoagulation and photodynamic therapy).

Searches were conducted in Ovid MEDLINE, the Cochrane Central Register of Controlled Trials, and the Cochrane Database of Systematic Reviews from 2008 (searches in the 2009 review were conducted through July 2008) to February 2015 (eAppendix 1 in the Supplement) and reference lists. An updated search conducted on January 6, 2016, using the same databases identified no new studies that would affect the conclusions or understanding of the evidence and therefore the related USPSTF recommendation.

Two reviewers evaluated each study on the basis of predefined criteria. For studies on screening and diagnostic accuracy, we included studies of asymptomatic adults 65 years or older without known impaired visual acuity (based on current corrected vision) who have not sought care for evaluation of vision problems. We included randomized clinical trials (RCTs) of vision screening performed in primary care or community-based settings vs no screening, delayed screening, or usual care (eg, targeted screening) and evaluated visual acuity, vision-related quality of life, functional capacity, mortality, cognition, or harms. We included studies of diagnostic accuracy of vision screening tests, questions, or questionnaires performed in primary care or community settings. For treatment, we included RCTs of asymptomatic adults (not restricted to age ≥65 years) with mild to moderate vision impairment (defined as best visual acuity worse than 20/40 but better than 20/200) that evaluated effects on the outcomes described above for corrective lenses, reading aids, or photorefractive surgery due to uncorrected refractive errors; vitamin and oxidants and vascular endothelial growth factor (VEGF) inhibitors for AMD; or cataract surgery. For screening and treatment, cohort studies were included when evidence from RCTs was insufficient. We excluded studies of screening and diagnostic testing performed in specialty settings and trials of treatment in patients with visual acuity worse than 20/200 or with other causes of vision loss. The selection of literature is summarized in Figure 2.

Details about the study design, patient population, setting, screening method, interventions, analysis, and results were abstracted. Two investigators independently applied criteria developed by the USPSTF¹¹ to rate the quality of each study as good, fair, or poor (eAppendix 2 in the Supplement). Discrepancies were resolved through consensus.

The aggregate internal validity (quality) of the body of evidence for each KQ was assessed as good, fair, or poor using methods developed by the USPSTF,¹¹ based on the quality of studies, precision of estimates, consistency of results between studies, and directness of evidence.¹¹ Data synthesis was based on evidence from the 2009 review as well as new evidence. A meta-analysis on effectiveness of VEGF inhibitors vs placebo for wet AMD was performed using a random-effects model with Review Manager 5.2 (Nordic Cochrane Centre) to calculate pooled relative risks (RRs) and absolute risk differences. The meta-analysis was stratified by the VEGF inhibitor used. Results were considered statistically significant if the P value was less than .05 based on 2-sided testing, and statistical heterogeneity was measured using the I².

Key Question 1. Does vision screening in asymptomatic older adults result in improved vision, morbidity or mortality, quality of life, functional status, or cognition?

Key Question 2. Are there harms of vision screening?

No new trials of vision screening were identified since 2008. Three cluster randomized trials (n = 4728) of vision screening performed as part of a multicomponent screening intervention in older adults (mean age, 76-81 years) were included in the 2009 USPSTF review⁸ (Table 1 and eTable 1 in the Supplement). The trials found no difference between vision screening vs no vision screening, usual care, or delayed screening on vision and other clinical outcomes after follow-up of 6 months to 5 years.^13-15 In the highest-quality and largest trial (n = 3346),¹⁵ universal vision screening identified a greater percentage of patients with impaired visual acuity and correctable impairment (27%) than did targeted screening (3.1%), yet there was no difference in likelihood of visual acuity worse than 20/60 after 3- to 5-year follow-up (37% vs 35%; relative risk [RR], 1.07; 95% CI, 0.84-1.36). In this trial, 18 of 40 patients (45%) advised to see an optician after vision screening actually received new lenses and 41 of 75 persons (55%) eligible for referral to an ophthalmologist had clear evidence of a referral, which could have attenuated potential benefits. Other reasons for lack of benefit in the screening trials may include the high loss to follow-up in all trials, similar frequency of vision disorder detection and treatment in the screening and control groups in 1 trial,¹⁴ use of a screening question to identify persons for further testing in 1 trial,¹⁴ and low uptake of recommended interventions in 1 trial.¹³ No study addressed harms of vision screening.

One additional screening trial did not meet inclusion criteria because it was conducted in a specialty setting.¹⁶ It found vision screening by an optometrist in frail elderly persons increased the risk for falls (2.45 falls/patient vs 1.68 falls/patient; rate ratio, 1.57; 95% CI, 1.20-2.05) along with a non–statistically significant increased risk for fractures (10% vs 5.7%; RR, 1.74; 95% CI, 0.97-3.11) after 1 year compared with usual care.¹⁶ Screening led to new eyeglasses or referral for further treatment for 47% of study participants. A subsequent report from this study also found no difference between groups in improvement in vision or vision-related quality of life after 1 year.¹⁷

Key Question 3. What is the accuracy of screening for early impairment in visual acuity due to uncorrected refractive error, cataracts or age-related macular degeneration?

The 2009 USPSTF review⁸ included 8 cross-sectional studies on the diagnostic accuracy of screening for impaired visual acuity in older adults (Table 2 and eTable 2 in the Supplement).^18-25 Four studies found screening questions or questionnaires had low accuracy for identifying persons with impaired visual acuity compared with the Snellen eye chart^19,20,23 or an ophthalmologic examination.²⁴ Positive likelihood ratios ranged from 1.19 to 3.23 and negative likelihood ratios ranged from 0.23 to 0.78. Four studies^18,21,24,25 found no visual acuity test had both high sensitivity and specificity compared with a detailed ophthalmologic examination, resulting in positive likelihood ratios that ranged from 1.00 to 8.07 and negative likelihood ratios that ranged from 0.32 to 1.00. Two studies reported areas under the receiver operating characteristic curves of 0.66 and 0.83.^18,21 One study found the Amsler grid had poor accuracy for identifying visual conditions (positive likelihood ratio 1.65 and negative likelihood ratio 0.91).¹⁸ A study published in 1988 (n = 50) reported that 100% of patients with cataract and 75% of patients with AMD were correctly identified by a geriatrician compared with an ophthalmologist, with no false positives.²²

Three fair-quality cross-sectional studies (reported in 2 publications) published subsequent to the 2009 review evaluated the diagnostic accuracy of screening tests in primary care settings (Table 2 and eTable 2 in the Supplement).^26,27 Two studies (n = 180 and 200) found that a computerized vision screening tool or a flip chart version of the test were not accurate compared with a detailed eye examination.²⁶ Optimal sensitivity (0.80) and specificity (0.68) were observed with the combination of abnormal high-contrast visual acuity (threshold >0.19 logarithm of the minimal angle of resolution) or abnormal near visual acuity, resulting in a positive likelihood ratio of 2.5 and a negative likelihood ratio of 0.29. The flip chart instrument performed similarly, based on the low-contrast visual acuity test alone (sensitivity 0.75 and specificity 0.77, for a positive likelihood ratio of 3.26 and negative likelihood ratio of 0.32). A third study (n = 371) compared the scores on the Minimum Data Set (MDS) 2.0 Vision Patterns section against a standard visual acuity test (Early Treatment Diabetic Retinopathy Study chart) for detecting impaired visual acuity.²⁷ Diagnostic accuracy was poor. Using a cutoff score of 1 or greater (0 indicating adequate vision and scores of 1-3 various degrees of impairment), sensitivity of the MDS Visual Patterns section for detecting visual acuity worse than 20/40 was 0.52 and specificity 0.75, for a positive likelihood ratio of 2.11 and a negative likelihood ratio of 0.64.

Key Question 4. Does treatment of early impairment in visual acuity due to uncorrected refractive error, cataracts, or AMD lead to improved visual acuity, morbidity, mortality, vision-related quality of life, functional status, or cognition?

We identified no new study of treatment vs no treatment for mild uncorrected refractive errors on vision, vision-related quality life, or functional outcomes. The 2009 USPSTF review⁸ found that refractive lenses and refractive surgery²⁸ were highly effective at restoring normal or near-normal visual acuity, based on a large body of observational data and accumulated clinical experience. It also included 2 randomized trials that reported beneficial effects of corrective lenses on vision-related quality of life, but not in functional status.^29,30 A later report from 1 of these studies,³⁰ published subsequent to the 2009 USPSTF review, also found no effects on function or cognitive status³¹; however, 3 observational studies found refractive surgery was associated with improved quality of life.^32-34

The 2009 USPSTF review⁸ found that more than 90% of patients undergoing cataract surgery achieved visual acuity of 20/40 or better based on observational studies.³⁵ It also included 1 trial that found immediate cataract surgery (within 4 weeks) decreased the risk of falls compared with routine surgery (12 months’ wait): 1.00/1000 patient days vs 1.52/1000 patient days (rate ratio, 0.66; 95% CI, 0.40-0.96).³⁶ Two cohort studies that were not in the 2009 USPSTF review found no association of cataract surgery vs no surgery with cognitive function or quality of life after 4 months³¹ and 1 year,³⁷ although visual acuity improved after surgery in both studies.

The 2009 USPSTF review⁸ included 1 large, good-quality (n = 2556) randomized trial, the Age-Related Eye Disease Study (AREDS) study.³⁸ AREDS reported results stratified according to the severity of AMD at baseline. Among the subgroup of patients in whom treatment is currently recommended (AREDS categories 3 and 4), AREDS found an antioxidant and zinc combination effective for lower likelihood of AMD progression after 6 years of follow-up (adjusted odds ratio [OR], 0.66; 95% CI, 0.47-0.93), although the difference in the likelihood of losing 15 or more letters of visual acuity was not statistically significant (adjusted OR, 0.75; 95% CI, 0.55-1.02). Ten-year follow-up results from AREDS are now available and are consistent with prior results; antioxidant supplements alone (OR, 0.70; 95% CI, 0.56-0.88) or with added zinc (OR, 0.66; 95% CI, 0.53-0.83) were associated with decreased risk of AMD progression vs placebo among persons with AREDS categories 3 and 4 AMD, and the combination was associated with decreased risk of visual acuity loss (46% vs 54%; OR, 0.71; 95% CI, 0.57-0.88).³⁹ The rates of AMD progression were 34% with the combination and 44% with placebo. Mortality outcomes were reported for AREDS severity categories 2, 3, and 4 (n = 3476). Zinc was also associated with a significantly decreased risk of all-cause mortality (22% vs 25%; adjusted HR, 0.83; 95% CI, 0.73-0.95) and cardiovascular mortality (adjusted RR, 0.80; 95% CI, 0.64-0.99), but there was no significant decrease in cancer mortality risk (adjusted RR, 0.84; 95% CI, 0.65-1.08).

A smaller, good-quality trial (n = 300) published since the 2009 USPSTF review found no difference between daily supplementation with fish oil capsules vs placebo in risk of visual acuity loss of 15 or more letters after 3 years (17.8% vs 16.3%; RR, 1.25; 95% CI, 0.69-2.26), although fish oil was associated with decreased risk of developing cataracts, worsening cataract, or need for cataract surgery (50.0% vs 62.5%; RR, 0.80; 95% CI, 0.64-0.99).⁴⁰ (RRs and CIs calculated based on proportions reported in the original article.⁴⁰) Evidence on other vitamins and minerals for dry AMD remains limited, with no clear effects on AMD progression or visual acuity (Table 3, Table 4, and eTable 3 in the Supplement).^41-44

The 2009 USPSTF review⁸ included 4 good-quality trials (reported in 3 publications, n = 184 to 716) of intravitreal injection with VEGF inhibitors vs sham therapy.^45-47 In the 2009 USPSTF review, pooled results were reported separately for pegaptanib (2 trials) and ranibizumab (2 trials); both VEGF inhibitors were associated with better visual acuity outcomes vs sham injections. A meta-analysis based on all 4 of these trials found VEGF inhibitors associated with greater likelihood for a gain of 15 or more letters in visual acuity (RR, 2.92; 95% CI, 1.20 to 7.12; I² = 76%), but the absolute risk difference was not statistically significant (10%; 95% CI, −7% to 27%). VEGF inhibitors were associated with greater likelihood of having vision 20/200 or better vs sham injection (RR, 1.47; 95% CI, 1.30 to 1.66; I² = 42%; absolute risk difference, 24%; 95% CI, 12% to 37%) after 1 year (Figure 3 and Figure 4). Beneficial effects were also observed in the MARINA trial after 2 years.⁴⁵ One trial each found intravitreal injection with VEGF inhibitors was associated with small improvements in likelihood of driving among those driving at baseline⁴⁸ and in vision-related function.⁴⁹

The MARINA trial found no difference between ranibizumab vs placebo in all-cause mortality (2% vs 3%; RR, 0.91; 95% CI, 0.34-2.44) or vascular mortality (1% vs 2%; RR, 0.74; 95% CI, 0.21-2.60) after 2 years.⁴⁵ In the other trials, there were no deaths⁴⁷ or mortality was not reported.⁴⁶

Key Question 5. Are there harms of treating early impairment in visual acuity?

We identified no new study on harms of treatment for uncorrected refractive error compared with no treatment. The 2009 USPSTF review⁸ included 1 small study (n = 156) that reported a higher risk of falls in older adults using multifocal lenses compared with unifocal lenses (48% vs 37%; adjusted OR, 2.29; 95% CI, 1.06-4.92).⁵⁰ Three studies reported that incidence of keratitis ranged from 0.3 to 3.6 cases per 10 000 contact lens wearers.^51-53 A meta-analysis reported rates of corneal ectasia of 0% to 0.87% based on 5 studies of laser-assisted in situ keratomileusis (LASIK) and rates of keratitis of 0% to 3.4% based on 6 studies of LASIK and 4 studies of laser-assisted subepithelial keratomileusis (LASEK).²⁸

We identified no new study of harms of cataract surgery vs no surgery. The 2009 USPSTF review included 3 systematic reviews^35,54,55 of observational studies on harms of cataract surgery, which reported pooled rates of posterior lens opacification of 28% after 5 years and 0.13% for endophthalmitis.

We identified no new studies on harms of treatment for AMD vs no treatment. The 2009 USPSTF review⁸ found use of antioxidant vitamins and mineral supplements not associated with increased risk of most adverse events.⁴¹ One trial published subsequent to the 2009 USPSTF review found no difference between supplement use vs placebo in risk of any adverse events (93% vs 89%; RR, 1.05; 95% CI, 0.97-1.13), serious adverse events (31% vs 30%; RR, 1.04; 95% CI, 0.72-1.49), or serious ocular adverse events (8.2% vs 7.0%; RR, 1.18; 95% CI, 0.50-2.75)⁴⁰; one other trial published subsequent to the 2009 USPSTF review found no difference in risk of withdrawals due to adverse events (7.1% vs 2.3%; RR, 3.00; 95% CI, 0.33-28).⁴³ One of 2 trials found VEGF inhibitors associated with greater likelihood of withdrawal vs sham therapy^45,46; there were no differences in serious or other adverse events, but estimates for those outcomes were imprecise.

Table 5 summarizes the evidence reviewed for this update. Quiz Ref IDWe identified no new trials of vision screening vs no screening, delayed screening, or usual care. Three fair- to good-quality cluster randomized trials included in the 2009 USPSTF review⁸ that enrolled more than 4700 patients found vision screening in older adults as part of a multicomponent screening intervention in primary care settings to be no more effective than no vision screening, delayed screening, or usual care.^13-15 A fourth trial found optometrist screening associated with an increased risk of falls in frail elderly individuals.¹⁶

Conclusions regarding the suboptimal diagnostic accuracy of vision screening tests in primary care settings are also unchanged from the 2009 USPSTF review. Two new studies found that the accuracy of a computer-based screening tool was limited, and 1 study found that a questionnaire performed poorly as a screening test.^26,27Quiz Ref ID The 2009 USPSTF review found that no screening question is comparable in accuracy with tests of visual acuity for identifying impaired visual acuity^{19,20,23,24,56} and that the Snellen test is inaccurate compared with a detailed eye examination for identifying visual conditions identified on a comprehensive ophthalmological examination. However, the clinical importance of asymptomatic conditions identified on an ophthalmologic examination is unclear and may vary depending on the condition. For example, treatments for cataracts may still be successful after the development of impaired visual acuity, whereas impaired visual acuity due to AMD could be irreversible. Although the Snellen test remains the most widely used tool to measure visual acuity in primary care settings, no clinically relevant reference standard exists to determine its diagnostic accuracy, in part because the Snellen test is often considered the standard for assessing visual acuity in clinical practice. There remains insufficient evidence to assess the accuracy or utility of pinhole testing, the Amsler grid, visual acuity tests other than the Snellen test, physical examination, or funduscopic examination performed in primary care settings.

Conclusions from the 2009 USPSTF review regarding the effectiveness of treatments vs no treatment for common causes of impaired visual acuity also remain unchanged. Based primarily on observational studies, a very high proportion of patients experience favorable vision-related outcomes after treatment for impaired visual acuity due to refractive error and cataracts.⁸ Correction of refractive error and cataract removal are also associated with improvement in vision-related quality of life, although randomized trials and cohort studies have not shown clear effects on measures of general function, cognition, or depression.^29-31,37,57

For dry AMD, evidence showing the effectiveness of antioxidant vitamins and minerals for slowing progression of disease or improving visual acuity remains largely restricted to the large AREDS trial.^38,41 Extended (10-year) follow-up from AREDS is now available, showing continued benefits.³⁹ Antioxidants included in the AREDS formulation have been found to be associated with congestive heart failure (vitamin E⁵⁸) and lung cancer in smokers (beta-carotene^59,60) when prescribed for prevention of cancer or cardiovascular disease, although such harms were not observed in AREDS.

For wet AMD, evidence reviewed in the 2009 USPSTF review found intravitreal injection with VEGF inhibitors to be effective treatment options with a relatively low incidence of serious harms, although they may be associated with an increased risk of acute decline in visual acuity.⁶¹ As detailed in the full review, photodynamic therapy and laser photocoagulation also appear to be associated with decreased risk of vision loss in patients with wet AMD but have been replaced as first-line therapy with VEGF inhibitors in most patients because of the risk of acute visual loss, need for retreatment (photodynamic therapy), and risk of permanent retinal damage (laser photocoagulation).¹²

Our evidence review has limitations. We excluded non–English language studies, which could introduce language bias. However, we identified no relevant non–English language studies, and some research found that exclusion of non–English language studies has little effect on conclusions of reviews of noncomplementary and alternative therapies.⁶² In addition, trials of therapy for dry AMD evaluated heterogeneous vitamins, antioxidants, and other supplements and could not be pooled. There were also too few randomized trials to perform reliable assessments for publication bias.⁶³

Quiz Ref IDWe identified important research gaps. Evidence indicates that screening can identify older patients with decreased visual acuity and there are effective treatments for common causes of impaired visual acuity, yet screening was not associated with improved clinical outcomes. Well-designed studies in primary care settings are needed to identify optimal methods for vision screening and to develop effective strategies for linking older adults with impaired visual acuity to appropriate care, which would help maximize the potential benefits of screening. Studies are needed on the diagnostic accuracy and utility of funduscopic examination, pinhole testing, the Amsler grid, and non-Snellen visual acuity tests in primary care settings for supplementing or replacing the Snellen visual eye chart. Evidence on effectiveness of antioxidants and vitamins for dry AMD remains largely dependent on a single large trial³⁸ and would be strengthened by other, well-designed trials that are also designed to adequately evaluate potential harms associated with components of the supplements, such as congestive heart failure and lung cancer risk. More studies are needed to understand the potential association between correction of refractive errors and risk of falls¹⁶ and, if an association is present, to identify methods for mitigating these risks. Research is also needed to understand the effectiveness of new therapies that are being investigated for their effectiveness in AMD, such as statins⁶⁴ and complement inhibitors (eg, protease inhibitors).⁶⁵

Quiz Ref IDScreening can identify persons with impaired visual acuity, and effective treatments are available for common causes of impaired visual acuity, such as uncorrected refractive error, cataracts, and dry or wet AMD. However, direct evidence found no significant difference between vision screening in older adults in primary care settings vs no screening for improving visual acuity or other clinical outcomes.

Corresponding Author: Roger Chou, MD, 3181 SW Sam Jackson Park Rd, Mail Code BICC, Portland, OR 97239 (chour@ohsu.edu).

Author Contributions: Dr Chou had full access to all of the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis.

Study concept and design: Chou.

Acquisition, analysis, or interpretation of data: Chou, Dana, Bougatsos, Grusing, Blazina.

Drafting of the manuscript: Chou, Dana, Bougatsos, Grusing.

Critical revision of the manuscript for important intellectual content: Chou, Blazina.

Statistical analysis: Chou, Dana.

Obtained funding: Chou.

Administrative, technical, or material support: Dana, Bougatsos, Grusing, Blazina.

Study supervision: Chou, Bougatsos.

Conflict of Interest Disclosures: All authors have completed and submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest and none were reported.

Funding/Support: This research was funded by the Agency for Healthcare Research and Quality (AHRQ) under a contract to support the USPSTF.

Role of the Sponsor: Investigators worked with USPSTF members and AHRQ staff to develop the scope, analytic framework, and key questions for this review. AHRQ had no role in study selection, quality assessment, or synthesis. AHRQ staff provided project oversight; reviewed the report to ensure that the analysis met methodological standards, and distributed the draft for peer review. Otherwise, AHRQ had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; preparation, review, or approval of the manuscript; and decision to submit the manuscript for publication.

Additional Information: A draft version of this evidence report underwent external peer review from 5 content experts (Neil M. Bressler, MD, Wilmer Eye Institute, Johns Hopkins University School of Medicine; Zahra Jessa, PhD, BSc, MCOptom, Moorfields Eye Hospital, Royal National Institute of Blind People, London; Gianni Virgili, MD, Careggi Hospital Eye Clinic, University of Florence, Italy; Liam Smeeth, MBChB, FRCGP, FFPH, FRCP, MSc, PhD, London School of Hygiene and Tropical Medicine; Nancy Weintraub, MD, David Geffen School of Medicine, University of California at Los Angeles) and 3 federal partners: Food and Drug Administration/Center for Drug Evaluation and Research; National Institute on Aging/National Institutes of Health; and the Veterans Health Administration. Comments were presented to the USPSTF during its deliberation of the evidence and were considered in preparing the final evidence review.

Editorial Disclaimer: This evidence report is presented as a document in support of the accompanying USPSTF Recommendation Statement. It did not undergo additional peer review after submission to JAMA.