Draft Recommendation Statement
Vision in Children Ages 6 Months to 5 Years: Screening
This opportunity for public comment expires on March 27, 2017 at 8:00 PM EST
Note: This is a Draft Recommendation Statement. This draft is distributed solely for the purpose of receiving public input. It has not been disseminated otherwise by the USPSTF. The final Recommendation Statement will be developed after careful consideration of the feedback received and will include both the Research Plan and Evidence Review as a basis.
Recommendations made by the USPSTF are independent of the U.S. government. They should not be construed as an official position of the Agency for Healthcare Research and Quality or the U.S. Department of Health and Human Services.
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In an effort to maintain a high level of transparency in our methods, we open our draft Recommendation Statements to a public comment period before we publish the final version.
Draft: Recommendation Summary
|Children ages 3 to 5 years|
The USPSTF recommends vision screening at least once in all children ages 3 to 5 years to detect amblyopia or its risk factors.
|Children younger than age 3 years|
The USPSTF concludes that the current evidence is insufficient to assess the balance of benefits and harms of vision screening in children younger than age 3 years.
Send Us Your Comments
In an effort to maintain a high level of transparency in our methods, we open our draft Recommendation Statements to a public comment period before we publish the final version.
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.
One of the most important causes of vision abnormalities in children is amblyopia (or “lazy eye”). Amblyopia is an alteration in the visual neural pathway in the developing brain that can lead to permanent vision loss in the affected eye.1, 2 It usually occurs unilaterally but can occur bilaterally. Risk factors associated with the development of amblyopia include strabismus (ocular misalignment), visual deprivation caused by media opacity (e.g., cataracts), and certain refractive errors (e.g., anisometropia). Other common causes of vision abnormalities are nonamblyopic strabismus and nonamblyopic refractive error.1 The Table provides definitions for the common causes of visual impairment. Among preschool-aged children, 1% to 6% have amblyopia or its risk factors (strabismus, anisometropia, or both) that, if left untreated, could lead to amblyopia.1, 3-6 Early identification of vision abnormalities could prevent the development of amblyopia.
The USPSTF found adequate evidence that vision screening tools are accurate in detecting visual abnormalities, including refractive errors, strabismus, and amblyopia. The USPSTF found inadequate evidence to compare accuracy across age groups (<3 vs. ≥3 years). Many studies did not include children younger than age 3 years.
Benefits of Early Detection and Treatment
The USPSTF found adequate evidence that treatment of amblyopia or its risk factors in children ages 3 to 5 years leads to improved visual acuity. The USPSTF determined that the magnitude of improvement in visual acuity is of moderate benefit. The USPSTF found inadequate evidence that treatment reduced long-term amblyopia or improved school performance, functioning, or quality of life. Limited evidence suggests that screening can potentially reduce psychosocial harms. The USPSTF found inadequate evidence that treatment of amblyopia or its risk factors in children younger than age 3 years leads to improved visual outcomes.
Harms of Early Detection and Treatment
The USPSTF found adequate evidence to assess harms of screening tests in children ages 3 to 5 years, including higher false-positive rates in low-prevalence populations. False-positive screening results may lead to overdiagnosis or unnecessary treatment. Limited evidence suggests that patching in children ages 3 to 5 years does not worsen visual acuity in the nonamblyopic eye but may be associated with psychological harms, such as child or parent upset or worry. The USPSTF found adequate evidence to bound the potential harms of screening and treatment in children ages 3 to 5 years as small, based on the nature of the interventions. The USPSTF found inadequate evidence on the harms of treatment in children younger than age 3 years.
The USPSTF concludes with moderate certainty that vision screening to detect amblyopia or its risk factors in children ages 3 to 5 years has a moderate net benefit. The USPSTF concludes that the benefits of vision screening to detect amblyopia or its risk factors in children younger than age 3 years are uncertain, and that the balance of benefits and harms cannot be determined for this age group.
Draft: Clinical Considerations
Patient Population Under Consideration
This recommendation applies to children ages 6 months to 5 years.
Assessment of Risk
Although all children ages 3 to 5 years are at risk of vision abnormalities and should be screened, there are some risk factors that increase risk. Amblyopia risk factors include strabismus, refractive errors, and media opacity.1, 2 Additional risk factors associated with amblyopia, strabismus, or refractive error include family history in a first-degree relative, prematurity, low birth weight, maternal substance abuse, maternal smoking during pregnancy, and poor parental education.1, 7-12
A variety of screening tests are used to identify visual abnormalities in children in primary care settings. Visual acuity tests screen for visual deficits associated with amblyopia and refractive error. Ocular alignment tests screen for strabismus. Steroacuity testing, or the assessment of depth perception, is often omitted, and may be performed incorrectly when attempted in a primary care setting.1, 13 In children younger than age 3 years, screening can include vision assessment, including external inspection for gross abnormalities, fixation and follow test (visual acuity), red reflex test (media opacity), and pupil examination with a penlight. The corneal light reflex test, which assesses for strabismus, can be done at any age, including in preverbal children.1, 13 Instrument-based vision screening (i.e., autorefractors and photoscreeners) may be used in very young children, including infants. Autorefractors are computerized instruments that detect refractive errors; photoscreeners detect amblyopia risk factors (ocular alignment and media opacity) and refractive errors.1, 14 In addition, vision assessment in children older than age 3 years could include external inspection of the eyes, red reflex test, cover-uncover test (strabismus), evaluation of visual acuity with charts (e.g., Snellen, Lea Symbols® [Lea-Test, Helsinki, Finland], and HOTV [Precision Vision, La Salle, IL]), autorefractors and photoscreeners, and stereopsis tests.1, 13
The USPSTF did not find adequate evidence to determine the optimal screening interval in children ages 3 to 5 years.
Treatment depends on the specific condition, but could include correction of any underlying refractive error with the use of corrective lenses, occlusion therapy for amblyopia (e.g., eye patching, atropine eye drops, or Bangerter occlusion foils), or surgical interventions for some causes of strabismus. Clinicians may use vision therapy for various eye conditions, such as individualized eye muscle exercises, over a period of several months, either alone or in combination with occlusion therapy, correction of refractive errors, or both.
Suggestions for Practice Regarding the I Statement
Potential Preventable Burden
Untreated amblyopia is not likely to spontaneously resolve.1, 15, 16 Treatment efficacy decreases as children age, with a risk of irreversible visual loss.1, 17-19 Amblyopia often becomes irreversible if the child is not treated by age 6 to 10 years.1 Untreated visual abnormalities can result in short-and long-term physical and psychological harms, such as accidents and injuries, bullying, poor visual motor skills, depression and anxiety, poor self-esteem, and problems at school and work.20-24
Vision screening is routinely offered in most primary care clinics. Screening rates in children age 3 years are approximately 40% and increase with age.1, 25 One survey reported that 3% of pediatricians began vision screening at age 6 months.1, 26 Typical components of vision screening include assessments of visual acuity and strabismus. Younger children are often unable to cooperate with some of the clinical screening tests performed in clinical practice, such as visual acuity testing, which may result in false-positive results. Some clinical practice guidelines now recommend handheld autorefraction and photoscreening as alternative approaches to screening in children age 6 months or older due to improved child cooperation and improved accuracy.1, 27 One potential disadvantage of using photoscreening is the need for external interpretation of screening results with some types of photoscreeners. Children with positive findings should be referred for a complete eye examination to confirm the presence of vision abnormalities and for further treatment.
Draft: Other Considerations
Research Needs and Gaps
The USPSTF identified several gaps in the evidence. Well-designed studies are needed to identify the optimal age for screening initiation and appropriate screening intervals. Additional studies are needed to determine the best screening approach and most favorable combinations of screening tests. There is also a need for studies that examine the benefits and harms of preschool vision screening, treatment of children younger than age 3 years, and the effects on long-term outcomes, such as quality of life, school performance, developmental trajectory, or functioning.
Burden of Disease
The prevalence of amblyopia, strabismus, and anisometropia ranges from 1% to 6% in children younger than age 6 years in the United States.1, 3-6 Strabismus is the most common cause of amblyopia in children younger than age 3 years; in children ages 3 to 6 years, strabismus and anisometropia contribute equally.17 Among children younger than age 6 years, 4% have myopia and up to 20% have hyperopia. Five percent to 10% of preschool-aged children have astigmatism.1, 18-20 Amblyopia may significantly increase the risk of severe visual abnormalities or blindness in the event of vision loss in the nonamblyopic eye.1, 28, 29 The estimated lifetime risk of vision loss for persons with amblyopia is 1.2% or greater.1, 28, 29
Scope of Review
The USPSTF commissioned a systematic evidence review to update its 2011 recommendation on screening for amblyopia and its risk factors in children.30 The review examined the evidence on the accuracy of vision screening tests and the benefits and harms of vision screening and treatment. Surgical interventions for refractory strabismus, cataracts, ptosis, or other conditions were considered to be out of scope for this review.
Accuracy of Screening Tests
The USPSTF found 34 fair-quality studies (n=45,588 observations) that assessed the accuracy of various screening tests: visual acuity tests (six studies), stereoacuity tests (four studies), ocular alignment tests (one study), a combination of clinical tests (four studies), autorefractors (16 studies), photoscreeners (11 studies), and retinal birefringence scanning (one study).1
Fourteen studies recruited participants from ophthalmology clinics; 16 studies recruited from Head Start, community, or school settings; two studies were conducted in primary care settings; and one study did not report its setting. Across the studies, screening was administered by diverse personnel such as pediatricians, orthoptists, ophthalmologists, nurses, and Head Start staff.1
More than half of the studies (k=19) were conducted in the United States. The remaining studies took place in Canada (k=5), Europe (k=7), and New Zealand or Australia (k=3). Study sample sizes ranged from 63 to 4,040 participants. The age of study participants ranged from 6 months to 6 years. About one third of study participants were younger than age 3 years; most were age 3 years and older.1 Many of the studies of photoscreeners (n=6,187) included children younger than age 3 years; four of the 15 studies evaluating autorefractors (n=16,610) included children younger than age 3 years.1
The Vision in Preschoolers (VIP) study (n ≤4,040) provided data for several publications. The VIP study evaluated the accuracy of multiple screening tests for a wide range of visual conditions. It preferentially enrolled children ages 3 to 5 years from Head Start with amblyopia, amblyopia risk factors, reduced visual acuity, or strabismus.1, 31 Phase I of the study compared the accuracy of 11 screening tests.31 Tests were conducted in specially equipped vans that provided a standard environment with minimal distractions. Phase II of the study compared the performance of nurse versus lay screeners and focused on four of the 11 screening tests.32 The VIP study evaluated the accuracy of screening for a broader range of conditions than most other studies, including significant nonamblyogenic refractive error.
Visual Acuity Tests
Six fair-quality studies evaluated visual acuity tests (Lea Symbols or HOTV). Three publications from the VIP study (n=6,019) assessed the accuracy of Lea Symbols for identifying amblyopia risk factors or clinically significant nonamblyogenic refractive error.1 In phase I of the VIP study, visual acuity testing with Lea Symbols was associated with a positive likelihood ratio (PLR) of 6.1 (95% CI, 4.8 to 7.6)31 for detecting amblyopia risk factors or significant nonamblyogenic refractive error; among the 3-, 4-, and 5-year-old age groups, PLRs ranged from 5.95 to 7.39.1 The overall negative likelihood ratio (NLR) was 0.43 (95% CI, 0.38 to 0.50); it ranged from 0.39 to 0.47 among the 3-, 4-, and 5-year-old age groups. In phase II of the VIP study, PLRs were 4.9 (95% CI, 4.0 to 6.0) and 3.7 (95% CI, 3.0 to 4.7), respectively, for nurse and lay screeners. The NLR was 0.57 (95% CI, 0.52 to 0.62) for nurse screeners and 0.70 (95% CI, 0.65 to 0.76) for lay screeners.1, 32
Three additional studies (n=773) assessed the accuracy of Lea Symbols for detecting amblyopia risk factors, significant refractive error, or astigmatism. PLRs ranged from 1.6 to 5.7 and NLRs ranged from 0.05 to 0.21.1
The VIP study (n=3,121) found that the HOTV test was associated with an overall PLR of 4.9 (95% CI, 3.9 to 6.1) for detecting amblyopia risk factors or significant nonamblyogenic refractive error.1, 31 PLRs ranged from 3.76 to 6.83 in 3- to 5-year-old age groups.1 Overall, the NLR was 0.52 (95% CI, 0.46 to 0.58); it ranged from 0.47 to 0.62 in 3- to 5-year-old age groups.1, 31
Four fair-quality studies (n=7,801) evaluated stereoacuity tests.1 Most of the studies found PLRs ranging from 3.6 to 4.9. NLRs were in the minimal range for detecting amblyopia risk factors or significant nonamblyogenic refractive error and in the moderate range for detecting refractive error or strabismus.1
Ocular Alignment Tests
Combinations of Clinical Tests
Four fair-quality studies (n=1,854) assessed a combination of tests of visual acuity, stereoacuity, and ocular alignment.1 Three of the four studies found PLRs ranging from 12 to 17.1 The fourth study, which found a smaller PLR of 4.8 (95% CI, 2.8 to 8.4), was the smallest (n=141) of the studies. The four studies had NLRs ranging from 0.10 to 0.91.1
Eleven fair-quality studies (6,187 observations; n=63 to 3,121) assessed photoscreeners. Generally, most studies reported moderate PLRs and small NLRs.1
Retinal Birefringence Scanning
One fair-quality study (n=102) evaluated the Pediatric Vision Scanner (REBIScan, Boston). The PLR was 10.4 (95% CI, 5.6 to 19.4) and the NLR was 0.89.1
Direct Comparisons of Different Types of Screening Tests
Phase I of the VIP study compared 11 screening tests among 3- to 5-year-olds. The Lea Symbols and HOTV visual acuity tests and the Retinomax (Nikon, Melville, NY), SureSight (Welch Allyn, Skaneateles Falls, NY), and Power Refractor (Plusoptix, Nuremberg, Germany) autorefractors had higher sensitivity for identifying any visual condition compared with the Random Dot E stereoacuity test (StereoOptical, Chicago), Randot Stereo Smile Test II (StereoOptical, Chicago), iScreen photoscreener (iScreen, Memphis, TN), and MTI photoscreener (Medical Technologies, Riviera Beach, FL). However, likelihood ratios were similar. PLRs were generally in the moderate range and NLRs were in the small to minimal range, with overlapping confidence intervals.1, 31
Age and Testability
Five studies evaluated whether screening accuracy differs by age. Most studies of test accuracy (n=45,588 observations) did not enroll participants younger than age 3 years. Accuracy did not clearly differ among preschool-aged children in different age groups (3 years or older).1
Testability (the ability to complete screening tests) may limit the usefulness of some clinical screening tests in children younger than age 3 years. Testability was reported in many of the included studies; however, few reported data stratified by age or for children younger than age 3 years. Testability generally exceeded 80% to 90% in children age 3 years, with small increases through age 5 years. Studies that evaluated testability found better testability in older children (age ≥3 years); low testability rates were reported for visual acuity and stereoacuity tests in children younger than age 3 years. Some data suggest that photoscreeners have high testability rates for children as young as age 1 year.1
Effectiveness of Early Detection and Treatment
No eligible randomized, controlled trials directly compared screening with no screening. No available studies evaluated school performance, other functional outcomes, or quality of life. No eligible studies evaluated atropine or vision therapy.1
The USPSTF evaluated two fair-quality studies; a nested trial within a population-based cohort study (Avon Longitudinal Study of Parents and Children [ALSPAC]). The study assessed prevalence of amblyopia at age 7.5 years (using visual acuity testing); school performance, function, or quality of life outcomes were not evaluated.1, 33, 34 The ALSPAC nested, randomized trial (n=3,490) compared earlier, intensive screening (at age 8, 12, 18, 25, 31, and 37 months) with one-time screening at age 37 months.1, 33 The trial showed that periodic screening (including clinical examination, visual acuity test, and cover-uncover test) from ages 8 to 37 months was associated with a 1% decrease in the prevalence of amblyopia at age 7.5 years compared with one-time screening at age 37 months; however, the difference was only statistically significant for one of two definitions of amblyopia (interocular difference in acuity ≥0.2 logMAR [logarithm of the minimum angle of resolution], 1.5% vs. 2.7%; relative risk, 0.55 [95% CI, 0.29 to 1.04]; interocular difference in acuity ≥0.3 logMAR, 0.6% vs. 1.8%; relative risk, 0.35 [95% CI, 0.15 to 0.86]).1, 33 The ALPSPAC cohort study (n=6,081) compared screening at age 37 months with no screening and found no statistically significant difference in the prevalence of amblyopia at age 7.5 years for three definitions of amblyopia.1, 33
ALSPAC had several study limitations. A major limitation was the high overall attrition (about 55%) in both studies. Additional limitations included inadequate randomization and the inability to parse out the effects of earlier screening compared with repeated screening. As a result of these important limitations, the USPSTF did not include ALSPAC as direct evidence; however, the results support an indirect chain of evidence.1, 33, 34
One fair- and two good-quality trials (n=417) of older preschool-aged children (ages 3 to 5 years) assessed treatment benefits.1, 35-37 These trials evaluated patching for amblyopia or amblyopia risk factors. Two trials compared patching with no patching (children were pretreated with eyeglasses if indicated in both groups).1, 36, 37 One trial compared patching plus eyeglasses versus eyeglasses alone versus no treatment.1, 35 Study sample size ranged from 60 to 180.1 One of the three trials (patching plus eyeglasses vs. eyeglasses alone vs. no treatment) enrolled screen-detected children.1, 35 Followup duration varied from 5 or 12 weeks to 1.5 years.1, 35 Trials were conducted in the United States or the United Kingdom.1, 35-37 The trials reported best corrected visual acuity and improvement in visual acuity (secondary outcome).1, 35-37 Results could not be pooled due to differences in study populations (e.g., eligibility criteria, baseline visual acuity), outcome measures, comparisons, and length of followup.1
The trials reported that patching improves visual acuity of the amblyopic eye by an average of less than 1 line on the Snellen chart after 5 to 12 weeks in children with amblyopia risk factors who were pretreated with glasses.1 More children treated with patching experienced improvement of at least 2 lines on the Snellen chart than children with no patching (45% vs. 21%; p=0.003). Patching plus eyeglasses improved visual acuity by about 1 line on the LogMAR chart after 1 year (0.11 logMAR [95% CI, 0.05 to 0.17]) in children with amblyopia risk factors who were not pretreated with eyeglasses.1 Eyeglasses improved visual acuity by less than 1 line on the LogMAR chart after 1 year (0.08 logMAR [95% CI, 0.02 to 0.15]) in children with amblyopia risk factors. Benefits were greater for children with more severe visual impairment at baseline. Children with worse baseline visual acuity had greater improvement with patching plus eyeglasses or eyeglasses alone.1
Potential Harms of Screening and Treatment
Potential harms of vision screening of preschool-aged children include psychosocial effects such as labeling and anxiety, unnecessary referrals due to false-positive screening results, overdiagnosis, and unnecessary use of corrective lenses or treatments to prevent amblyopia. Studies of screening tests (n=9,723) showed high false-positive rates in low-prevalence populations. Studies with a lower prevalence (<10%) of vision abnormalities showed much higher rates of false positives (usually >75%), whereas studies with a high prevalence had lower false-positive rates (usually <35%).1 No studies reported other measures of psychosocial distress, labeling, or anxiety. The prospective cohort study (n=4,473) from ALSPAC evaluated bullying in 8-year-olds among a subgroup of children who were treated with patching. The likelihood of being bullied was lower for children who were offered screening at age 37 months than for those who were not screened (25.7% vs. 47.1%; p=0.033; adjusted odds ratio, 0.39 [95% CI, 0.16 to 0.92]).1, 33
Potential harms of treatment include harms to the nonamblyopic eye, loss of visual acuity in the amblyopic eye, psychological harms (e.g., child happiness, behavior problems, parental worry or upset), inverse amblyopia, and patch allergy. One fair-quality trial and two good-quality trials (n=417) assessed treatment harms.1, 35-37, 38 The three trials did not report similar outcomes. None of the included studies evaluated atropine drops. One trial compared patching (n=87) versus no patching (n=93) and demonstrated that worsening visual acuity in the nonamblyopic eye did not differ between groups at 5 weeks (2.4% vs. 6.8%; p=0.28).1, 36 A trial comparing patching plus eyeglasses (n=59), eyeglasses alone (n=59), and no treatment (n=59) found no significant difference in loss of visual acuity in the amblyopic eye between treatment groups at 1 year.1, 35 In a subanalysis of one trial (patching plus eyeglasses vs. eyeglasses alone vs. no treatment), the psychological harms of treatment were evaluated in 144 out of 177 study participants.1, 35, 38 Few differences were observed between the treatment groups for child happiness or behavioral problems. Child or parental worry or upset about treatment were greater with patching than with eyeglasses alone (29% vs. 85% at age 4 years; p=0.03; 26% vs. 62% at age 5 years; p=0.005).1, 38 The study did not compare the eyeglasses and patching group with the nontreatment group for the psychological harms identified.1, 38 No participants experienced an adverse event (e.g., inverse amblyopia, patch allergy) in one trial (n=60) that compared patching with no patching.1, 37
Estimate of Magnitude of Net Benefit
Treatment of amblyopia is associated with moderate improvements in visual acuity in children ages 3 to 5 years, which are likely to result in permanent improvements throughout life. The USPSTF concluded that the benefits are moderate because untreated amblyopia results in permanent, uncorrectable vision loss; the benefits of screening and treatment are potentially experienced over a child's lifetime. The USPSTF found adequate evidence on harms of screening (i.e., higher false-positive rates in low- prevalence populations). The USPSTF found adequate evidence to bound the potential harms of treatment as small. Therefore, the USPSTF concludes with moderate certainty that the overall net benefit is moderate.
How Does Evidence Fit With Biological Understanding?
Amblyopia is a functional reduction in visual acuity characterized by abnormal processing of visual images by the brain. It is associated with conditions that affect binocular vision, such as strabismus, anisometropia, and media opacity. The loss in visual acuity is unlikely to resolve spontaneously if left untreated. Therefore, screening in preschool-aged children seems to be consistent with the current biological understanding of amblyopia and the importance of detecting it during a critical period in children’s development.
Draft: Update of Previous USPSTF Recommendation
This recommendation updates the USPSTF 2011 recommendation, in which the USPSTF recommended vision screening for amblyopia and its risk factors in children ages 3 to 5 years (B recommendation). The USPSTF concluded that the evidence was insufficient to assess the balance of benefits and harms of vision screening in children younger than age 3 years (I statement). The current recommendation reaffirms the previous recommendation.
Draft: Recommendations of Others
In 2016, the American Academy of Pediatrics, American Association for Pediatric Ophthalmology and Strabismus, American Academy of Certified Orthoptists, and American Academy of Ophthalmology released a joint clinical report recommending preschool vision screening. The joint report recommends that children ages 6 months to 3 years should have their vision assessed with physical examination (e.g., external inspection, fixation and follow test, red reflex test, and pupil examination). Instrument-based vision screening (autorefraction, photoscreening), may be added, when available, for children ages 1 to 3 years. Visual acuity screening may be attempted at age 3 years using HOTV or Lea Symbols; children ages 4 to 5 years should have visual acuity assessed using HOTV or Lea Symbols, the cover-uncover test, and the red reflex test.1, 39
The American Academy of Family Physicians recommends vision screening in all children at least once between the ages of 3 and 5 years to detect amblyopia or its risk factors; it concluded that the current evidence is insufficient to assess the balance of benefits and harms of vision screening in children younger than age 3 years.40
The American Optometric Association recommends that infants receive an initial vision screening at birth. Regular comprehensive eye examinations should occur at age 6 months, age 3 years, and prior to entry into first grade; eye examinations should then occur at 2-year intervals unless children are considered to be at high risk for vision abnormalities.41
1. Jonas DE, Amick HR, Wallace IF, Feltner C, Vander Schaaf EB, Brown CL, Baker C. Vision Screening in Children Ages 6 Months to 5 Years. Evidence Synthesis No. 153. AHRQ Publication No. 17-05228-EF-1. Rockville, MD: Agency for Healthcare Research and Quality; 2017.
3. McKean-Cowdin R, Cotter SA, Tarczy-Hornoch K, et al; Multi-Ethnic Pediatric Eye Disease Study Group. Prevalence of amblyopia or strabismus in Asian and non-Hispanic white preschool children: Multi-Ethnic Pediatric Eye Disease Study. Ophthalmology. 2013;120(10):2117-24.
4. Friedman DS, Repka MX, Katz J, et al. Prevalence of amblyopia and strabismus in white and African American children aged 6 through 71 months: the Baltimore Pediatric Eye Disease Study. Ophthalmology. 2009;116(11):2128-34.e1-2.
5. Multi-Ethnic Pediatric Eye Disease Study (MEPEDS) Group. Prevalence and causes of visual impairment in African-American and Hispanic preschool children: the Multi-Ethnic Pediatric Eye Disease Study. Ophthalmology. 2009;116(10):1990-2000.e1.
6. Ying GS, Maguire MG, Cyert LA, et al; Vision In Preschoolers (VIP) Study Group. Prevalence of vision disorders by racial and ethnic group among children participating in Head Start. Ophthalmology. 2014;121(3):630-6.
7. van Hof-Van Duin J, Evenhuis-van Leunen A, Mohn G, Baerts W, Fetter WP. Effects of very low birth weight (VLBW) on visual development during the first year after term. Early Hum Dev. 1989;20(3-4):255-66.
8. Cotter SA, Varma R, Tarczy-Hornoch K, et al; Joint Writing Committee for the Multi-Ethnic Pediatric Eye Disease Study and the Baltimore Pediatric Eye Disease Study Groups. Risk factors associated with childhood strabismus: the Multi-Ethnic Pediatric Eye Disease and Baltimore Pediatric Eye Disease Studies. Ophthalmology. 2011;118(11):2251-61.
9. Tarczy-Hornoch K, Varma R, Cotter SA, et al; Joint Writing Committee for the Multi-Ethnic Pediatric Eye Disease Study and the Baltimore Pediatric Eye Disease Study Groups. Risk factors for decreased visual acuity in preschool children: the Multi-Ethnic Pediatric Eye Disease and Baltimore Pediatric Eye Disease Studies. Ophthalmology. 2011;118(11):2262-73.
10. McKean-Cowdin R, Varma R, Cotter SA, et al; Joint Writing Committee for the Multi-Ethnic Pediatric Eye Disease Study and the Baltimore Pediatric Eye Disease Study Groups. Risk factors for astigmatism in preschool children: the Multi-Ethnic Pediatric Eye Disease and Baltimore Pediatric Eye Disease Studies. Ophthalmology. 2011;118(10):1974-81.
11. Borchert MS, Varma R, Cotter SA, et al; Joint Writing Committee for the Multi-Ethnic Pediatric Eye Disease Study and the Baltimore Pediatric Eye Disease Study Groups. Risk factors for hyperopia and myopia in preschool children: the Multi-Ethnic Pediatric Eye Disease and Baltimore Pediatric Eye Disease Studies. Ophthalmology. 2011;118(10):1966-73.
12. Quinn GE, Dobson V, Davitt BV, et al; Early Treatment for Retinopathy of Prematurity Cooperative Group. Progression of myopia and high myopia in the Early Treatment for Retinopathy of Prematurity study: findings at 4 to 6 years of age. J AAPOS. 2013;17(2):124-8.
14. Miller JM, Lessin HR; American Academy of Pediatrics Section on Ophthalmology; Committee on Practice and Ambulatory Medicine; American Academy of Ophthalmology; American Association for Pediatric Ophthalmology and Strabismus; American Association of Certified Orthoptists. Instrument-based pediatric vision screening policy statement. Pediatrics. 2012;130(5):983-6.
16. Carlton J, Karnon J, Czoski-Murray C, Smith KJ, Marr J. The clinical effectiveness and cost-effectiveness of screening programmes for amblyopia and strabismus in children up to the age of 4-5 years: a systematic review and economic evaluation. Health Technol Assess. 2008;12(25):iii, xi-194.
18. Flynn JT, Schiffman J, Feuer W, Corona A. The therapy of amblyopia: an analysis of the results of amblyopia therapy utilizing the pooled data of published studies. Trans Am Ophthalmol Soc. 1998;96:431-50; discussion 50-3.
19. American Academy of Ophthalmology Pediatric Ophthalmology/Strabismus Panel. Preferred Practice Pattern® Guidelines: amblyopia. 2012. https://www.aao.org/preferred-practice-pattern/amblyopia-ppp--september-2012. Accessed January 19, 2017.
25. Marsh-Tootle WL, Funkhouser E, Frazier MG, Crenshaw K, Wall TC. Knowledge, attitudes, and environment: what primary care providers say about pre-school vision screening. Optom Vis Sci. 2010;87(2):104-11.
28. Rahi J, Logan S, Timms C, Russell-Eggitt I, Taylor D. Risk, causes, and outcomes of visual impairment after loss of vision in the non-amblyopic eye: a population-based study. Lancet. 2002;360(9333):597-602.
29. van Leeuwen R, Eijkemans MJ, Vingerling JR, Hofman A, de Jong PT, Simonsz HJ. Risk of bilateral visual impairment in individuals with amblyopia: the Rotterdam study. Br J Ophthalmol. 2007;91(11):1450-1.
31. Schmidt P, Maguire M, Dobson V, et al; Vision in Preschoolers Study Group. Comparison of preschool vision screening tests as administered by licensed eye care professionals in the Vision In Preschoolers Study. Ophthalmology. 2004;111(4):637-50.
32. Vision in Preschoolers Study Group. Preschool vision screening tests administered by nurse screeners compared with lay screeners in the Vision In Preschoolers Study. Invest Ophthalmol Vis Sci. 2005;46(8):2639-48.
33. Williams C, Harrad RA, Harvey I, Sparrow JM; ALSPAC Study Team. Screening for amblyopia in preschool children: results of a population-based, randomised controlled trial. Avon Longitudinal Study of Pregnancy and Childhood. Ophthalmic Epidemiol. 2001;8(5):279-95.
34. Williams C, Northstone K, Harrad RA, Sparrow JM, Harvey I; ALSPAC Study Team. Amblyopia treatment outcomes after screening before or at age 3 years: follow up from randomised trial. BMJ. 2002;324(7353):1549.
35. Clarke MP, Wright CM, Hrisos S, Anderson JD, Henderson J, Richardson SR. Randomised controlled trial of treatment of unilateral visual impairment detected at preschool vision screening. BMJ. 2003;327(7426):1251.
36. Wallace DK, Edwards AR, Cotter SA, et al; Pediatric Eye Disease Investigator Group. A randomized trial to evaluate 2 hours of daily patching for strabismic and anisometropic amblyopia in children. Ophthalmology. 2006;113(6):904-12.
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40. American Academy of Family Physicians. Clinical preventive service recommendation: visual difficulties and impairment. http://www.aafp.org/patient-care/clinical-recommendations/all/visual.html. Accessed January 19, 2017.
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Draft: Table. Definitions
|Amblyopia||Functional reduction in visual acuity characterized by abnormal processing of visual images; established by the brain during a critical period of vision development|
|Strabismus||Ocular misalignment; most common cause of amblyopia|
|Anisometropia||Asymmetric refractive error between the two eyes that causes image suppression in the eye with the larger error|
|Astigmatism||Blurred vision at any distance due to abnormal curvature of the cornea or lens|
|Hyperopia||Farsightedness; visual images come to focus behind the retina|
|Myopia||Nearsightedness; visual images come to focus in front of the retina|
Internet Citation: Draft Recommendation Statement: Vision in Children Ages 6 Months to 5 Years: Screening. U.S. Preventive Services Task Force. February 2017.