The US Preventive Services Task Force (USPSTF) makes recommendations about the effectiveness of specific preventive care services for patients without obvious related signs or symptoms.

It bases its recommendations on the evidence of both the benefits and harms of the service and an assessment of the balance. The USPSTF does not consider the costs of providing a service in this assessment.

The USPSTF recognizes that clinical decisions involve more considerations than evidence alone. Clinicians should understand the evidence but individualize decision making to the specific patient or situation. Similarly, the USPSTF notes that policy and coverage decisions involve considerations in addition to the evidence of clinical benefits and harms.

Importance

Impairment of visual acuity is a serious public health problem in older adults. In 2011, about 12% of US adults aged 65 to 74 years and 15% of those 75 years or older reported having problems seeing, even with glasses or contact lenses.

Detection

The USPSTF found convincing evidence that screening with a visual acuity test can identify persons with a refractive error. The USPSTF found convincing evidence that screening questions are not as accurate as visual acuity testing for assessing visual acuity. The USPSTF found adequate evidence that visual acuity testing alone does not accurately identify early age-related macular degeneration (AMD) or cataracts.

Benefits of Detection and Early Treatment

The USPSTF found inadequate overall evidence on the benefits of screening, early detection, and treatment to provide a coherent assessment of the overall benefits. Several studies evaluated the direct benefit of screening and reported no reductions in vision disorders or vision-related function in screened populations; however, these studies had limitations, including differing control interventions, high loss to follow-up, and low uptake of treatment. The USPSTF found adequate evidence that early treatment of refractive error, cataracts, and AMD improves or prevents loss of visual acuity.

Harms of Detection and Early Treatment

The USPSTF found inadequate evidence on the harms of screening. The USPSTF found adequate evidence that early treatment of refractive error, cataracts, and AMD may lead to harms that are small to none.

USPSTF Assessment

The USPSTF concludes that the evidence is insufficient to assess the balance of benefits and harms of screening for impaired visual acuity in older adults. The evidence is lacking to provide a coherent assessment, and the balance of benefits and harms cannot be determined.

Patient Population Under Consideration

This recommendation applies to asymptomatic adults 65 years or older who do not present to their primary care clinician with vision problems.

Suggestions for Practice Regarding the I Statement

Potential Preventable Burden

In 2011, about 12% of US adults aged 65 to 74 years and 15% of those 75 years or older reported having problems seeing, even with glasses or contact lenses.¹ The prevalence of AMD is 6.5% in adults older than 40 years and increases with age (2.8% in those aged 40–59 years and 13.4% in those aged ≥60 years).² About half of all cases of bilateral low vision (ie, best-corrected visual acuity of <20/40) in adults 40 years and older are caused by cataracts. The prevalence of cataracts increases sharply with age; an estimated 50% of US adults 80 years or older have cataracts.¹ The prevalence of hyperopia requiring a correction of +3.0 diopters or more ranges from about 5.9% in US adults aged 50 to 54 years, to 15.2% in adults aged 65 to 69 years, to 20.4% in adults 80 years or older.¹

Older age is an important risk factor for most types of visual impairment. Additional risk factors for cataracts are smoking, alcohol use, ultraviolet light exposure, diabetes, corticosteroid use, and black race. Risk factors for AMD include smoking, family history, and white race.¹

Potential Harms

The harms of screening in a primary care setting have not been adequately studied. Overall, the potential for harms from treatment are small to none. Harms of treatment of refractive error include a potential for increased falls with the use of multifocal lenses; infectious keratitis with the use of contact lenses, laser-assisted in situ keratomileusis (LASIK), or laser-assisted subepithelial keratectomy (LASEK); and corneal ectasia with LASIK. Harms of cataract surgery include posterior lens opacification and endophthalmitis. Treatment of AMD with antioxidant vitamins and mineral supplements is not associated with increased risk of most serious adverse events.

Although there appears to be benefit in longer-term outcomes, a systematic review found that treatment of AMD with laser photocoagulation was associated with greater risk of acute loss of 6 or more lines of visual acuity vs no treatment at 3 months (relative risk [RR], 1.41 [95% CI, 1.08–1.82]).³ Pooled estimates report a non–statistically significant association bewteen photodynamic therapy and risk of acute loss of 20 or more letters of visual acuity vs placebo at 7 days (RR, 3.75 [95% CI, 0.87–16]) (3 trials).^{4, 5} One of 2 trials found that treatment of wet AMD with intravitreal vascular endothelial growth factor (VEGF) inhibitor therapy was associated with greater likelihood of withdrawal vs sham therapy; there were no differences in serious or other adverse events, but estimates were imprecise.^{1, 4, 6, 7}

Current Practice

About half of US adults older than 65 years reported having an eye examination within the last 12 months in a 2007 study.⁸

Screening Tests

A visual acuity test (eg, the Snellen eye chart) is the usual method for screening for visual acuity impairment in the primary care setting. Screening questions are not as accurate as visual acuity testing for identifying visual acuity impairment. Evidence on the use of other tests for vision screening in primary care, such as the pinhole test (a test for refractive error), the Amsler grid (a test of central vision to detect AMD), genetic testing, or funduscopy (visual inspection of the interior of the eye), is lacking.

Treatment

Several types of treatment are effective for improving visual acuity. Corrective lenses improve visual acuity in patients with a refractive error. Treatment of cataracts through surgical removal of the cataract is effective for improving visual acuity. Treatment of exudative (or wet) AMD includes laser photocoagulation, verteporfin, and intravitreal injections of VEGF inhibitors. Antioxidant vitamins and minerals are an effective treatment for dry AMD.

Other Approaches to Prevention

This recommendation statement does not include screening for glaucoma. The USPSTF’s recommendations on screening for glaucoma and falls prevention are available on its website (www.uspreventiveservicestaskforce.org).

Research Needs and Gaps

More evidence is needed on accurate methods of screening in a primary care setting to identify disorders that do not manifest themselves through loss of visual acuity. More studies are needed that evaluate the link between vision screening in older adults and improved function, quality of life, and independence. Further studies are needed on the association between use of corrective lenses and risk of falls, including possible associations with changes in lens prescriptions and the use of multifocal glasses.

Burden of Disease

Vision impairment is common in older adults. Older adults have a higher prevalence of primary ocular disease and systemic diseases associated with ocular disease than younger adults; in addition, older adults also have normal age-related changes in vision (ie, presbyopia). In 2011, an estimated 12% of US adults aged 65 to 74 years and 15% of those 75 years or older reported vision loss.¹

Refractive error, AMD, and cataracts are common causes of vision impairment in older adults. Severe refractive error (requiring correction of ≥+3.0 diopters) affects an estimated 6% of US adults aged 50 to 54 years, 15% of adults aged 65 to 69 years, and 20% of adults 80 years or older.¹ About 60% of all cases of refractive error are deemed correctable to better than 20/40 visual acuity.⁹ In the United States, more than 15 million adults older than 65 years have cataracts, and it is the most common cause of blindness in black adults older than 40 years. Age-related macular degeneration affects 1.5 million older adults in the United States and is the most common cause of blindness in white adults.^{2, 10}

Scope of Review

In 2009, the USPSTF issued an I statement on screening for impaired visual acuity in older adults. To update this I statement, the USPSTF commissioned a systematic review to focus on evidence published since its last review. The USPSTF reviewed evidence on screening for visual acuity impairment associated with uncorrected refractive error, cataracts, and AMD in adults 65 years or older in the primary care setting. The USPSTF also reviewed the evidence on the benefits and harms of screening, the accuracy of screening, and the benefits and harms of treatment of early vision impairment due to uncorrected refractive error, cataracts, and AMD.

Accuracy of Screening Tests

Asking screening questions to elicit self-perceived problems with vision has been studied as a screening method. However, compared with a standard eye chart, screening questions are not accurate for identifying persons with vision impairment.^{1, 4}

In the United States, a standardized visual acuity test is the usual method for identifying the presence of vision impairment. Visual acuity tests assess the patient’s ability to recognize letters of different sizes arranged in rows from a prespecified distance (typically 20 feet). Standardized visual acuity tests are good at identifying refractive error.

Compared with a detailed ophthalmological examination, no visual acuity screening test has both high sensitivity and specificity for the diagnosis of any underlying visual condition (eg, AMD or cataracts). Few studies have focused on the accuracy of the Amsler grid, clinical examination, pinhole test, or fundus examination in the primary care setting. One study on the Amsler grid reported poor accuracy for detecting any visual condition compared with ophthalmological examination, and 1 study reported that geriatricians correctly identified most patients with cataracts and AMD through a clinical examination.^{1, 4}

Two studies from 2012 evaluated the accuracy of the Computer Vision Screen and its flip-chart version compared with a “gold standard” eye examination that included detailed history, symptoms, and a comprehensive eye examination. These studies reported moderate sensitivity (0.75 to 0.80) and specificity (0.68 to 0.77).¹¹ A third study from 2009 evaluated the accuracy of the Minimum Data Set 2.0 Vision Patterns section compared with a standard visual acuity test. The study reported poor accuracy, depending on the cutoff score; sensitivity ranged from 0.11 to 0.52 and specificity ranged from 0.25 to 0.96.¹² These studies had methodological limitations, including uncertainty as to whether the reference standard was interpreted independently from the screening test and the lack of a predefined threshold to determine a positive result.

Effectiveness of Early Detection and Treatment

There is limited direct evidence on the effectiveness of screening for visual impairment in the primary care setting. Three fair-quality cluster randomized clinical trials (RCTs) found no difference in vision and other clinical or functional outcomes between vision screening (as part of a multicomponent screening) with visual acuity testing or questions compared with usual care, no vision screening, or delayed screening.^13-15 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 of outcome assessors. Other limitations relevant to the primary care setting include that the recommended interventions are provided by eye care specialists and that many patients do not get the recommended glasses.

Consistent evidence shows that most older adults with a refractive error can 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 2005 systematic review of 179 RCTs and observational studies found that refractive surgery was highly effective at improving refractive error; 92% to 94% of persons with myopia and 86% to 96% of persons with hyperopia achieved visual acuity of 20/40 or better. However, most of these studies were done in younger adults, limiting its generalizability to older adults.¹⁶

Cataract surgery is consistently associated with improved visual acuity in observational studies. About 90% of patients have postoperative visual acuity better than 20/40.^{1, 4, 17} The effects of cataract surgery on vision-related quality of life and function are mixed. One trial reported a decreased risk of falls after immediate vs delayed cataract surgery (RR, 0.66 [95% CI, 0.40–0.96]).¹⁸ Another trial reported no effect on falls or fracture risk.¹⁹ Some studies showed improvements in measures of function and quality of life associated with cataract surgery, while others reported no effect on these measures. Evidence from observational studies on the effects of treatment on motor vehicle accidents and death is sparse and inconclusive. No randomized trials were identified that evaluated clinical outcomes associated with cataract surgery vs no surgery.

A systematic review from 2006 reported that antioxidants were effective for slowing the progression of dry AMD; its conclusions were primarily based on 1 large good-quality trial (the Age-Related Eye Disease Study).²⁰ It found that taking an antioxidant multivitamin (composed of vitamins C and E and beta-carotene with zinc) was associated with reduced likelihood of progression to advanced AMD (adjusted odds ratio [OR], 0.68); however, the between-group differences in the likelihood of losing measurable visual acuity did not reach statistical significance. A 10-year follow-up study of the Age-Related Eye Disease Study published in 2009 reported similar results; an antioxidant multivitamin with zinc was associated with reduced likelihood of progression of AMD (OR, 0.66 [95% CI, 0.53 to 0.83]). The likelihood of losing measurable visual acuity did reach statistical significance in this follow-up study (OR, 0.71 [95% CI, 0.57 to 0.88]).²¹

For wet AMD, laser photocoagulation is superior to no treatment in slowing the progression of vision loss (≥6 lines of visual acuity) after 2 years (RR, 0.67 [95% CI, 0.53 to 0.83]), although these studies had important limitations.³ Two good-quality systematic reviews of photodynamic therapy found verteporfin, a photoreactive agent, to be superior to placebo in preventing loss of visual acuity associated with wet AMD; quality-of-life outcomes were not reported.^{5, 22} Injection of VEGF inhibitors (eg, pegaptanib and ranibizumab) to suppress growth of abnormal blood vessels associated with wet AMD was effective in reducing risk of visual acuity loss (<15 letters of visual acuity) (RR, 1.46 [95% CI, 1.22 to 1.75]).^{4, 23} Evidence on vision-related functional outcomes is limited; 1 trial reported small improvements in vision-related functional scores in the treatment group, and 1 trial reported a higher likelihood of driving in the treatment group.¹

Potential Harms of Screening and Treatment

No studies are available on the harms of screening in a primary care setting. Several studies evaluated the harms of treatment of refractive error, cataracts, and AMD. Most of these studies are older and were reviewed for the 2009 USPSTF recommendation. Data on harms of treatment of refractive error in older adults are limited. A small observational study reported an association between multifocal lens use and increased risk of falls in older adults.²⁴ Serious harms, including vision loss, are rare as a result of contact lens use or refractive surgery. Corneal ectasia, a thinning and bulging of the cornea, is a known harm of refractive surgery and occurs at a median rate of 0.2%.^{1, 4} Cataract surgery can lead to posterior capsule opacification of the implanted lens, requiring further procedures; reported rates of this complication vary widely from 0.7% to 48%.^{17, 25} A systematic review from 1998 reported an incidence of 28% at 5 years.²⁶ Endophthalmitis, bullous keratopathy, dislocation of intraocular lens, macular edema, and retinal detachment are other complications associated with cataract surgery.

Pooled data on the harms of treatment of AMD from trials of antioxidant vitamins and minerals reported no association with withdrawal due to gastrointestinal symptoms.^{1, 4} The largest trial reported an increased risk of hospitalization due to genitourinary causes with zinc and an increased risk of yellowing skin with antioxidants; it found no association with death or lung cancer.^{1, 4} Two trials on the treatment of early AMD reported no association between supplement use and any adverse event, serious adverse events, serious ocular events, or withdrawal due to adverse events.¹

Treatment of wet AMD with laser photocoagulation is associated with increased risk of acute visual acuity loss at 3 months after the procedure but, as described earlier, is also associated with reduced risk of visual acuity loss at 2 years.^{1, 4} Photodynamic therapy with verteporfin carries an initial risk of acute visual acuity loss and greater risk of back pain related to the infusion.⁵ Other reported harms of photodynamic therapy include visual disturbance, injection site reactions, and photosensitivity. Potential harms associated with intravitreal injections of VEGF inhibitors include endophthalmitis, uveitis, increased intraocular pressure, traumatic lens injury, and retinal detachment.^{1, 4} In 3 trials, these outcomes were infrequent, and differences between the intervention and sham therapy groups were not statistically significant; however, estimates were imprecise, with wide CIs given the rarity of these outcomes.^{1, 6, 7, 27}

Estimate of Magnitude of Net Benefit

The limited direct evidence from 3 fair-quality cluster RCTs show no difference in vision and other clinical or functional outcomes between vision screening and usual care, no vision screening, or delayed screening.

Although visual acuity testing is adequate for identifying refractive error, it is inadequate for identifying early AMD or early cataracts in a primary care setting. Effective treatments are available for uncorrected refractive error, cataracts, and AMD. The overall harms are small; however, many of the treatments carry a small risk of 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 and overall and vision-related function, especially in older adults with screen-detected visual problems.

The limitations of the direct evidence and the inadequacy of the evidence on key pieces of indirect evidence prevent the USPSTF from developing a coherent assessment of the overall net benefit; therefore, the balance of benefits and harms cannot be determined.

Response to Public Comment

A draft version of this recommendation statement was posted for public comment on the USPSTF website from July 21 through August 17, 2015. The USPSTF received very few comments on the draft recommendation statement. One respondent requested that the USPSTF clarify that an I statement is not a recommendation against screening; the USPSTF plans to reinforce when communicating this recommendation statement that an I statement is not a recommendation for or against screening.

This recommendation is an update of the 2009 USPSTF recommendation on screening for impaired visual acuity in older adults, which also 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.

The American Optometric Association recommends that asymptomatic adults 61 years and older receive an eye examination every year.²⁸ The American Academy of Ophthalmology recommends a comprehensive eye examination that includes visual acuity testing and dilation every 1 to 2 years for all adults 65 years or older who do not have risk factors or more frequently if risk factors are present.²⁹ This recommendation is based on descriptive studies, case reports, and expert consensus. The American Academy of Family Physicians’ recommendation is consistent with that of the USPSTF statement: the current evidence is insufficient to assess the balance of benefits and harms of screening for impaired visual acuity, or vision impairment, in adults 65 years and older who have not reported problems with vision.³⁰ The American Congress of Obstetricians and Gynecologists recommends that vision assessment be a part of well-woman visits for all women 65 years or older.³¹

Members of the USPSTF at the time this recommendation was finalized† are Albert L. Siu, MD, MSPH, Chair (Mount Sinai School of Medicine, New York, and James J. Peters Veterans Affairs Medical Center, Bronx, New York); Kirsten Bibbins-Domingo, PhD, MD, MAS, Co-Vice Chair (University of California, San Francisco, San Francisco, California); David C. Grossman, MD, MPH, Co-Vice Chair (Group Health Research Institute, Seattle, Washington); Linda Ciofu Baumann, PhD, RN, APRN (University of Wisconsin, Madison, Wisconsin); Karina W. Davidson, PhD, MASc (Columbia University, New York, New York); Mark Ebell, MD, MS (University of Georgia, Athens, Georgia); Francisco A.R. García, MD, MPH (Pima County Department of Health, Tucson, Arizona); Matthew Gillman, MD, SM (Harvard Medical School and Harvard Pilgrim Health Care Institute, Boston, Massachusetts); Jessica Herzstein, MD, MPH (Independent Consultant, Washington, DC); Alex R. Kemper, MD, MPH, MS (Duke University, Durham, North Carolina); Alex H. Krist, MD, MPH (Fairfax Family Practice, Fairfax, and Virginia Commonwealth University, Richmond, Virginia); Ann E. Kurth, PhD, RN, MSN, MPH (New York University, New York, New York); Douglas K. Owens, MD, MS (Veterans Affairs Palo Alto Health Care System, Palo Alto, and Stanford University, Stanford, California); William R. Phillips, MD, MPH (University of Washington, Seattle, Washington); Maureen G. Phipps, MD, MPH (Brown University, Providence, Rhode Island); and Michael P. Pignone, MD, MPH (University of North Carolina, Chapel Hill, North Carolina).

† For a list of current USPSTF members, go to https://www.uspreventiveservicestaskforce.org/uspstf/about-uspstf/current-members.

Source: This article was first published in JAMA on March 1, 2016.

Conflict of Interest Disclosures: All authors have completed and submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest and none were reported. Authors followed the policy regarding conflicts of interest described at https://www.uspreventiveservicestaskforce.org/uspstf/about-uspstf/conflict-interest-disclosures.

Funding/Support: The USPSTF is an independent, voluntary body. The US Congress mandates that the Agency for Healthcare Research and Quality (AHRQ) support the operations of the USPSTF.

Disclaimer: Recommendations made by the USPSTF are independent of the US government. They should not be construed as an official position of AHRQ or the US Department of Health and Human Services.

Copyright Notice: USPSTF recommendations are based on a rigorous review of existing peer-reviewed evidence and are intended to help primary care clinicians and patients decide together whether a preventive service is right for a patient’s needs. To encourage widespread discussion, consideration, adoption, and implementation of USPSTF recommendations, AHRQ permits members of the public to reproduce, redistribute, publicly display, and incorporate USPSTF work into other materials provided that it is reproduced without any changes to the work of portions thereof, except as permitted as fair use under the U.S. Copyright Act.

AHRQ and the U.S. Department of Health and Human Services cannot endorse, or appear to endorse, derivative or excerpted materials, and they cannot be held liable for the content or use of adapted products that are incorporated on other Web sites. Any adaptations of these electronic documents and resources must include a disclaimer to this effect. Advertising or implied endorsement for any commercial products or services is strictly prohibited.

This work may not be reproduced, reprinted, or redistributed for a fee, nor may the work be sold for profit or incorporated into a profit-making venture without the express written permission of AHRQ. This work is subject to the restrictions of Section 1140 of the Social Security Act, 42 U.S.C. § 1320b-10. When parts of a recommendation statement are used or quoted, the USPSTF Web page should be cited as the source.

1. Chou R, Dana T, Bougatsos C, Grusing S, Blazina I. Screening for Impaired Visual Acuity in Older Adults: A Systematic Review to Update the 2009 U.S. Preventive Services Task Force Recommendation. Evidence Synthesis No. 127. AHRQ Publication No. 14-05209-EF-1. Rockville, MD: Agency for Healthcare Research and Quality; 2015.
2. Congdon N, Vingerling JR, Klein BE, West S, Friedman DS, Kempen J, et al; Eye Diseases Prevalence Research Group. Prevalence of cataract and pseudophakia/aphakia among adults in the United States. Arch Ophthalmol. 2004;122(4):487-94.
3. Virgili G, Bini A. Laser photocoagulation for neovascular age-related macular degeneration. Cochrane Database Syst Rev. 2007;(3):CD004763.
4. Chou R, Dana T, Bougatsos C. Screening for Visual Impairment in Older Adults: Systematic Review to Update the 1996 U.S. Preventive Services Task Force Recommendation. Evidence Synthesis No. 71. AHRQ Publication No. 09-05135-EF-1. Rockville, MD: Agency for Healthcare Research and Quality; 2009.
5. Wormald R, Evans J, Smeeth L, Henshaw K. Photodynamic therapy for neovascular age-related macular degeneration. Cochrane Database Syst Rev. 2007;(3):CD002030.
6. Rosenfeld PJ, Brown DM, Heier JS, Boyer DS, Kaiser PK, Chung CY, Kim RY; MARINA Study Group. Ranibizumab for neovascular age-related macular degeneration. N Engl J Med. 2006;355(14):1419-31.
7. Gragoudas ES, Adamis AP, Cunningham ET Jr, Feinsod M, Guyer DR; VEGF Inhibition Study in Ocular Neovascularization Clinical Trial Group. Pegaptanib for neovascular age-related macular degeneration. N Engl J Med. 2004;351(27):2805-16.
8. Zhang X, Saaddine JB, Lee PP, Grabowski DC, Kanjilal S, Duenas MR, Narayan KM. Eye care in the United States: do we deliver to high-risk people who can benefit most from it? Arch Opthalmol. 2007;125(3):411-8.
9. Vitale S, Cotch MF, Sperduto RD. Prevalence of visual impairment in the United States. JAMA. 2006;295(18):2158-63.
10. Centers for Disease Control and Prevention. Improving the Nation's Vision Health: A Coordinated Public Health Approach. Atlanta: Centers for Disease Control and Prevention; 2009. Accessed at https://www.cdc.gov/visionhealth/pdf/improving_nations_vision_health_508_final.pdf on 10 May 2019.
11. Jessa Z, Evans BJ, Thomson DW. The development & evaluation of two vision screening tools for correctable visual loss in older people. Ophthalmic Physiol Opt. 2012;32(4):332-48.
12. Swanson MW, McGwin G Jr, Elliott AF, Owsley C. The nursing home minimum data set for vision and its association with visual acuity and contrast sensitivity. J Am Geriatr Soc. 2009;57(3):486-91.
13. Eekhof J, De Bock G, Schaapveld K, Springer M. Effects of screening for disorders among the elderly: an intervention study in general practice. Fam Pract. 2000;17(4):329-33.
14. Smeeth L, Fletcher AE, Hanciles S, Evans J, Wormald R. Screening older people for impaired vision in primary care: cluster randomised trial. BMJ. 2003;327(7422):1027.
15. Moore AA, Siu A, Partridge JM, Hays RD, Adams J. A randomized trial of office-based screening for common problems in older persons. Am J Med. 1997;102(4):371-8.
16. Murray A, Jones L, Milne A, Fraser CM, Lourenço T, Burr J. A Systematic Review of the Safety and Efficacy of Elective Photorefractive Surgery for the Correction of Refractive Error. London: National Institute for Health and Clinical Excellence; 2005.
17. Powe NR, Schein OD, Gieser SC, Tielsch JM, Luthra R, Javitt J, Steinberg EP; Cataract Patient Outcome Research Team. Synthesis of the literature on visual acuity and complications following cataract extraction with intraocular lens implantation. Arch Ophthalmol. 1994;112(2):239-52.
18. Harwood RH, Foss AJ, Osborn F, Gregson RM, Zaman A, Masud T. Falls and health status in elderly women following first eye cataract surgery: a randomised controlled trial. Br J Ophthalmol. 2005;89(1):53-9.
19. Foss AJ, Harwood RH, Osborn F, Gregson RM, Zaman A, Masud T. Falls and health status in elderly women following second eye cataract surgery: a randomised controlled trial. Age Ageing. 2006;35(1):66-71.
20. Evans JR. Antioxidant vitamin and mineral supplements for slowing the progression of age-related macular degeneration. Cochrane Database Syst Rev. 2006;(2):CD000254.
21. Chew EY, Sperduto RD, Milton RC, et al. Risk of advanced age-related macular degeneration after cataract surgery in the Age-Related Eye Disease Study: AREDS report 25. Ophthalmology. 2009;116(2):297-303
22. Meads C, Salas C, Roberts T, Moore D, Fry-Smith A, Hyde C. Clinical effectiveness and cost-utility of photodynamic therapy for wet age-related macular degeneration: a systematic review and economic evaluation. Health Technol Assess. 2003;7(9):v-vi, 1-98.
23. Vedula SS, Krzystolik MG. Antiangiogenic therapy with anti-vascular endothelial growth factor modalities for neovascular age-related macular degeneration. Cochrane Database Syst Rev. 2008;(2):CD005139.
24. Lord SR, Dayhew J, Howland A. Multifocal glasses impair edge-contrast sensitivity and depth perception and increase the risk of falls in older people. J Am Geriatr Soc. 2002;50(11):1760-6.
25. Powe NR, Tielsch JM, Schein OD, Luthra R, Steinberg EP; Cataract Patient Outcome Research Team. Rigor of research methods in studies of the effectiveness and safety of cataract extraction with intraocular lens implantation. Arch Ophthalmol. 1994;112(2):228-38.
26. Schaumberg DA, Dana MR, Christen WG, Glynn RJ. A systematic overview of the incidence of posterior capsule opacification. Ophthalmology. 1998;105(7):1213-21.
27. Regillo CD, Brown DM, Abraham P, Yue H, Ianchulev T, Schneider S, Shams N. Randomized, double-masked, sham-controlled trial of ranibizumab for neovascular age-related macular degeneration: PIER Study year 1. Am J Ophthalmol. 2008;145(2):239-48.
28. American Optometric Association. Adult Vision: 19 to 40 Years of Age. St. Louis, MO: American Optometric Association; 2014. Accessed at http://www.aoa.org/patients-and-public/good-vision-throughout-life/adult-vision-19-to-40-years-of-age?sso=y on 9 July 2015.
29. Feder RS, Olsen TW, Prum BE Jr, et al. Comprehensive Adult Medical Eye Evaluation Preferred Practice Pattern(®) Guidelines. Ophthalmology. 2016;123(1):P209-36.
30. American Academy of Family Physicians. Clinical Preventive Service Recommendation: Visual Difficulties, Adults. Leawood, KS: American Academy of Family Physicians; 2015. Accessed at http://www.aafp.org/patient-care/clinical-recommendations/all/visual.html on 29 October 2015.
31. American Congress of Obstetricians and Gynecologists. Ages 65 Years and Older: Health Topics. Washington, DC: American Congress of Obstetricians and Gynecologists; 2015. Accessed at http://www.acog.org/About-ACOG/ACOG-Departments/Annual-Womens-Health-Care/FOR-PATIENTS/Pt-Health-Topics-Age-65-Years-and-Older on 9 July 2015.