TABLE 6

Diagnostic Accuracy Studies

Study (Year)Screening Test Definition of a Positive Screening TestReference StandardDefinition of a CaseType of Study, Age of Enrollees, Sample Size, and Proportion With ConditionSetting
Arthur et al27 (2009)PlusOptix autorefractor (previously the Power Refractor)
Anisometropia >1 D, astigmatism >1.25 D, myopia >3 D, hyperopia >3.5 D, anisocoria >1 mm, abnormal alignment
Comprehensive eye examination with cycloplegic refractionAnisometropia >1 D; astigmatism >1.25 D; myopia >3 D; hyperopia >3.5 D; anisocoria >1 mm; strabismusCross-sectional; 4–5 y; N = 307; amblyogenic risk factors: 13% (36/275)Screener, kindergarten, Canada, dental assistant
Barry and Konig28 (2001)Retinomax autorefractor
Acuity outside −1 to 3 D, cylindric power >1.5 D, or anisometropia >1 D
Second orthoptic examination (Lea single-symbol test, cover-uncover test, eye motility, and abnormal head posture), followed by ophthalmologic examination for abnormal, missing, or inconsistent resultsAny newly administered patching therapy or any newly administered patching therapy (visual acuity ≤ 0.4 [20/50] in either eye, or difference of visual acuity between eyes ≥2 log steps)Cross-sectional; 3 y; N = 404; amblyopia: 2.5% (10/404)Kindergarten, Germany, orthoptist
Barry and Konig29 (2003)Visual inspection, cover-uncover test, eye motility and head-posture examination, Lea symbols visual acuity test
Anatomic abnormality, manifest strabismus, or unstable refusion after uncovering, anomalies of eye motility and head posture, visual acuity worse than 10/25 or >1 line of difference between eyes and visual acuity in worse eye 10/20 to 10/17
Second orthoptic examination (Lea single-symbol test, cover-uncover test, eye motility, and abnormal head posture) using more stringent criteria, followed by ophthalmologic examination for abnormal, missing, or inconsistent resultsNewly administered spectacle therapy if the corrected visual acuity is ≤020/50 in either eye or difference of visual acuity of >2 logarithmic lines (except for myopia); any newly administered patching therapy in presence of risk factors such as monolateral strabismus or high refractive error (≥1.5 D, or astigmatism ≥3 D)Cohort; 3 y; N = 1180; amblyopia or amblyogenic risk factors: 2.3% (26/1114)Kindergarten, Germany, orthoptist
Berry et al30 (2001)MTI photoscreener
Presence of abnormal red reflex, asymmetric corneal light reflection, opacity, or crescent
Comprehensive eye examination with cycloplegic refractionMyopia ≥1.00 D, hyperopia ≥2.75 D, astigmatism >1.50 D, anisometropia >1.50 D, >1-mm difference in pupil size, any strabismus, any media opacity, any ptosis, any fundus abnormalityCross-sectional; preschool (subgroup); N = 51; amblyogenic risk factors: 45% (23/51)Pediatric ophthalmology clinic, United States, screener not described
Bertuzzi et al31 (2006)Lea symbols visual acuity test
Various cutoffs evaluated; results shown for: A, acuity (decimal score) 0.80; B, acuity (decimal score) 0.63
Comprehensive eye examination with cycloplegic refractionBilateral myopia ≥3 D, unilateral myopia >1.5 D, bilateral hyperopia ≥3 D, unilateral hyperopia ≥1 D, unilateral/bilateral astigmatism >1.5 D, lack of media transparency, any retinal or optic nerve abnormality; strabismusCross-sectional; 38–54 mo; N = 149; amblyogenic risk factors: 16% (23/143)Pediatric ophthalmology clinic, Italy, 38–54 mo, screener not described
Chang et al32 (2007)A, distance visual acuity; B, near visual acuity; C, NTU random-dot stereogram
A1, distance visual acuity worse than 0.5 at 3 y of age, 0.6 at 4 y of age, 0.7 at 5 y of age, and 0.8 at 6 y of age; A2, distance visual acuity worse than 0.7 at 3 y of age, 0.8 at 4 y of age, 0.9 at 5 y of age, and 1.0 at 6 y of age; B, near visual acuity worse than 0.7 at 3 y of age, 0.8 at 4 y of age, 0.9 at 5 y of age, and 1.0 at 6 y of age; C, stereoacuity worse than 300 s-arc
Comprehensive eye examination with cycloplegic refractionBest corrected distance visual acuity worse than 1.0Cross-sectional; preschool; N = 5232; amblyopia: 2.2% (115/5232)Public health service stations, Taiwan, preschool, nurse
Chui et al33 (2004)Lea symbols visual acuity test, Frisby stereoacuity test, and external visual inspection
Visual acuity 6/12 to 2 or worse in 1 or both eyes, difference in visual acuity of ≥2 lines between eyes, stereoacuity worse than 600 in on Frisby or worse than 400 in on Titmus, presence of constant or intermittent tropia, monofixation syndrome, myopia greater than −0.75 D, hyperopia >3.50 D, astigmatism ≥1.50 D, anisometropia ≥1.00 D, any other anomaly or inability to complete gold-standard examination
Comprehensive eye examination with cycloplegic refractionLea symbols visual acuity of 6/12 to 2 or worse in 1 or both eyes; difference in visual acuity of ≥2 lines between eyes; stereoacuity worse than 600 in on Frisby or worse than 400 in on Titmus; constant or intermittent tropia, monofixation syndrome; myopia −0.75 D or greater; hyperopia ≥3.50 D; astigmatism ≥1.50 D; anisometropia ≥1.00 D; any other abnormality that warranted follow-up; unable to complete gold-standard examinationCross-sectional; 35–58 mo; N = 178; amblyogenic risk factors: 13% (18/141)Not described, Canada, 35–58 mo, nurse
Cogen and Ottemiller34 (1992)Visiscreen 100 photoscreener
Presence of abnormal red reflex, asymmetric corneal light reflection, opacity, or crescent
Comprehensive eye examination with cycloplegic refraction (“when possible”)Hyperopia >4 D; myopia >5 D; astigmatism >2 D; anisometropia >1 D; strabismus; media opacityCross-sectional; 6 mo to 6 y; N = 127; any visual condition: 12% (13/113); refractive error: 5% (6/113); strabismus: 4% (5/113); refractive error + strabismus: 1% (1/113); media opacity: 1% (1/113)Pediatric ophthalmology clinic, United States, technician
Cooper et al35 (1999)A, Fortune Optical VRB-100, photoscreener; B, MTI photoscreener
Presence of abnormal red reflex, asymmetric corneal light reflection, opacity, or crescent
Comprehensive eye examination with cycloplegic refractionHyperopia >3.5 D; anisometropia >1 D; myopia >2 D; astigmatism >2 D; any media opacity or fundus abnormality affecting vision; manifest strabismusCase-control; 12–44 mo; N = 105; 61 cases (amblyopia), 44 controlsPediatric ophthalmology clinic, Australia, technician
Dahlmann-Noor et al36 (2009)PlusOptix autorefractor (previously called the Power Refractor)
Not reported
Comprehensive eye examination with cycloplegic refractionMyopia >1 D; hyperopia >3 D; anisometropia >1 D; astigmatism >1.5 DCross-sectional; 4–7 y; N = 126; A, myopia: 3% (3/108); B, hypermetropia: 39% (42/108); C, astigmatism: 12% (13/108); D, anisometropia: 24% (28/117)Pediatric ophthalmology clinic, United Kingdom, ophthalmologist, orthoptist, or ophthalmic nurse
Dahlmann-Noor et al37 (2009)PlusOptix autorefractor (previously called the Power Refractor)
Spherical component less than −1.0 D or >3.0 D, cylinder power >1.5 D, anisometropia of spherical component or of cylinder power >1.0 D
Orthoptist screening with distance acuity testing, cover test, extraocular movements, prism test, and Lang stereotest; comprehensive eye examination with cycloplegic refraction for abnormal autorefractor or orthoptist screening resultsHyperopia >3.0 D; myopia >1.0 D; strabismus; ptosisCross-sectional; 4–7 y; N = 288; reduced vision in 1 or both eyes, manifest strabismus, or ptosis: 12% (36/288)Preschool/kindergarten, United Kingdom
Ehrt et al38 (2007)Power Refractor autorefractor (now called the PlusOptix autorefractor)
Hyperopia ≥3.0 D, myopia ≤2.0 D, astigmatism ≥1.0 D, anisometropia ≥1 D
Comprehensive eye examination with cycloplegic refractionHyperopia ≥3 D; myopia ≥2 D; astigmatism ≥1 D; anisometropia ≥1 DCross-sectional; 0–7 y; N = 161; amblyogenic risk factors: 43% (70/161)Pediatric ophthalmology clinic, Germany
Guo et al39 (2000)A, Computer-photorefractor; B, noncycloplegic retinoscopy
Presence of abnormal red reflex, asymmetric corneal light reflection, opacity, or crescent
Comprehensive eye examination with cycloplegic refractionMyopia ≥1.50 D; hyperopia ≥2.75 D; astigmatism ≥1.75 D; anisometropia ≥2.00 D; media opacity ≥1.5 mm; strabismus ≥5°Cross-sectional; 9–50 mo; N = 300; amblyogenic risk factors: 56% (168/300)Pediatric ophthalmology clinic, China, screener not described
Hope and Maslin40 (1990)Random dot E stereogram
Unable to correctly identify the E at least 4 times in succession at 1 mo
Comprehensive eye examination with cycloplegic refraction for visual acuity worse than 4/4 with the letter-matching test or worse than 6/6 for Kays picture cards in children who failed random dot E stereogram, visual acuity screen, or near cover test; otherwise visual acuity screen or near cover test used as reference standardVisual acuity 6/12 or worse in either eye; manifest strabismusCross-sectional; 3–4 y; N = 176; refractive error or strabismus: 5% (9/168); refractive error: 5% (9/168); strabismus: 0.6% (1/168)Pediatric ophthalmology clinic, New Zealand, screener not described
Kemper et al41 (2005)SureSight autorefractor
SureSight manufacturer referral criteria (hyperopia >2.00 D, myopia >1.00 D, cylinder >1.00 D, or difference >1.00 D)
Comprehensive eye examination with cycloplegic refractionAnisometropia >1.5 D; hyperopia >3.50 D; myopia >3.00 D; media opacity >1 mm; astigmatism >1.5 D at 90° or 180° or >1.0 D in oblique axis; ptosis ≤1 mm margin reflex distance; visual acuity per age-appropriate standards; manifest strabismusCross-sectional; 0–5 y; N = 170; amblyopia: 17% (29/170); refractive error: 26% (45/170); strabismus: 18% (30/170); any visual impairment: 36% (62/170)Pediatric ophthalmology clinic, United States, orthoptist or pediatric ophthalmologist
Kennedy and Sheps42 (1989)A, Otago-type photoscreener (noncommercial); B, Snellen E or Stycar graded balls visual acuity test and Titmus stereotest
A, presence of abnormal red reflex, asymmetric corneal light reflection, opacity, or crescent; B, vision <20/40 in either eye or stereoacuity <80 s of arc
Comprehensive eye examination with cycloplegic refractionRefractive error >3.00 D; astigmatism >2.00 D; corneal or lens opacity; fundus abnormality; strabismusCross-sectional; ≤6 y; N = 236; amblyogenic risk factor: 42% (98/236)Pediatric ophthalmology clinic, Canada, technician
Kennedy et al43 (1995)iScreen photoscreener
Presence of abnormal red reflex, asymmetric corneal light reflection, opacity, or crescent
Comprehensive eye examination without cycloplegic refractionVisual acuity worse than 20/30; constant tropia present; refractive error greater than ±3.00 D in either eye with ±2 D astigmatism; corneal, lens, or fundus abnormalityCross-sectional; age not reported; N = 264; any visual condition: 8% (21/264); strabismus: 1.1% (3/264); refractive error: 4.2% (11/264); strabismus and refractive error: 0.8% (2/264); structural: 0.4% (1/264)Kindergarten, Canada, health care aide
Kennedy and Thomas44 (2000)A, Lea symbols visual acuity test; B, Retinomax K-plus autorefractor
Age 2–4 y: myopia >2.50 D, hyperopia >4.00 D, astigmatism >2.00 D, anisometropia >1.50 D; age 4–7 y: myopoia >1.50 D, hyperopia >4.00 D, astigmatism >1.50 D, anisometropia >1.50 D
Comprehensive eye examination with cycloplegic refraction (in patients <4 y old)Tropia, intermittent or otherwise; refractive error >3.50 D in both eyes; myopia >0.50 D; anisometropia >2.00 D; astigmatism >2.00 D; corneal or lens opacity; fundus abnormalityCross-sectional; 45% ≤6 y old; N = 449; amblyogenic risk factors: 64% (273/423)Pediatric ophthalmology clinic, Canada, technician
Matta et al45 (2008)PlusOptix autorefractor (previously called the Photo Refractor)
A, manufacturer's referral criteria: anisometropia ≥1.0 D, astigmatism ≥0.75 D, myopia ≥2.0 D for 1–2 y and ≥1.0 D for 3–5 y, hyperopia ≥1.0 D, anisocoria ≥1 mm; B, revised referral criteria: anisometropia ≥1.25 D, astigmatism ≥1.0 D, myopia ≥2.0 D for 1–2 y and ≥1.0 D for 3–5 y, hyperopia ≥1.25 D, anisocoria ≥1 mm
Comprehensive eye examination with cycloplegic refractionAnisometropia >1.5 D; any manifest strabismus; hyperopia >3.50 D; myopia >3.00 D; media opacity >1 mm; astigmatism >1.5 D; ptosis less than −1-mm margin reflex distance; visual acuity: per age-appropriate standardsCross-sectional or retrospective; 1–5 y (data obtained for this subgroup); N = 80; amblyogenic risk factors: 50% (40/80)Pediatric ophthalmology clinic, United States, screener not reported
Miller et al46 (1999)A, Lea symbols visual acuity test; B, MTI photoscreener; C, Nidek KM-500 Keratometry screener; D, Retinomax K-Plus autorefractor
A, visual acuity worse than 20/40; B, presence of abnormal red reflex, asymmetric corneal light reflection, opacity, or crescent; C, astigmatism ≥2.25 D in either eye; D, astigmatism ≥1.50 D in either eye
Cycloplegic refraction and retinoscopyFor ages <2, 2–4, and 4–7 y, respectively; myopia: >4.00 D, >2.50 D, or >1.50 D; hyperopia: >5.00 D, >4.00 D, or >1.50 D; astigmatism: >2.50 D, >2.00 D, or >1.50 D; anisometropia: >1.50 D (all age groups)Cross-sectional; 3–5 y; N = 245; significant refractive error: 31% (76/245); all had astigmatismHead Start program, United States (Native American population), Head Start staff
Miller et al47 (2001)Visiscreen 100 photoscreener
Media opacity, crescent, asymmetric corneal reflex
Cycloplegic refractionAstigmatism ≥2.00 D for children <48 mo of age and ≥1.50 D for children ≥48 mo of ageCross-sectional; 3–5 y; N = 379; astigmatism ≥1.00 D: 48% (182/379)Head Start program, United States (Native American population); trained testers
Molteno et al48 (1993)Otago-type photoscreener
Yellow or white fundal reflex, deviation of papillary light reflex, inequality of pupil size, any other visible defect
History, inspection, cover test, examination of ocular media, and fundoscopy through undilated pupils; cycloplegic refraction, dilated fundoscopy, and orthoptic examination with any abnormalitiesCorrected visual acuity worse than 20/20 in the worse eye; heterophoria, either marked with good binocular vision or moderate with some defect of binocular vision and including intermittent squint with well-developed binocular vision; anisometropia ≥0.5 DCross-sectional; not reported (“infants and children”); N = 1000; yellow or white fundal reflex, deviation of papillary light reflex, inequality of pupil size, any other visible defect: 34% (340/1000)Pediatric ophthalmology clinic, New Zealand, ophthalmologist
Morgan and Johnson49 (1987)Visiscreen 100 Photoscreener
Media opacity; crescent; asymmetric corneal reflex
Comprehensive eye examination with cycloplegic refractionHyperopia ≥2.50 D; myopia ≥1 D; anisometropia >1 D; astigmatism >2 DCross-sectional; 3 mo to 8 y; N = 63; any visual condition: 60% (34/57)Pediatric ophthalmology clinic, United States, technician
Newman and East50 (1999)Sheridan-Gardiner visual acuity; cover-uncover test; ocular movements and convergence; prism test; TNO screening plate; Snellen visual acuity
Visual acuity 6/6 or worse; manifest strabismus; decompensating heterophoria; abnormality of ocular movements; abnormal response to 20 base-out prism test; negative response to TNO screening-plate stereotest; any other ocular abnormality
Comprehensive eye examinationBest corrected Snellen line acuity of 6/12 or worse in either eye and/or an interocular difference of ≥2 Snellen linesRetrospective cohort; 3.5 y and at 5–6 y; N = 597; amblyopia: 2.5% (15/597)“Community setting,” United Kingdom, orthoptist
Ottar et al51 (1995) and Donahue et al59 (2002)MTI photoscreener
A, media opacity; strabismus; myopic crescent ≥1 mm; hyperopic crescent ≥2.5 mm; astigmatism ≥2 mm; difference between horizontal and vertical photographs of same eye; B, media opacity >1 mm; strabismus; myopic crescent ≥2.5 mm (4-mm pupillary diameter), ≥4.5 mm (6-mm pupillary diameter), or ≥6.5 mm (8-mm pupillary diameter); hyperopic crescent ≥2.5, ≥4.5, or ≥6.5 mm; astigmatism >1.5, >2.0, or >2.5 mm; anisometropia (no crescent in fellow eye): crescent ≥2.0, ≥3.5, or ≥4 mm; anisometropia (crescent in fellow eye): crescent ≥1 mm in fellow eye and 1-mm difference between eyes, ≤2.5 mm in fellow eye and 2-mm difference between eyes or ≥3 mm in fellow eye and 1-mm difference between eyes, or ≤3.5 mm in fellow eye and 2-mm difference between eyes or ≥4-mm crescent in fellow eye and 1-mm difference between eyes
Comprehensive eye examination with cycloplegic refractionA, myopia >1.00 D; hyperopia >2.75 D; astigmatism >1.00 D; anisometropia >1.50 D; any media opacity; any strabismus; any abnormality of posterior pole; B, myopia >3.00 D; hyperopia >3.50 D; astigmatism >1.50 D; anisometropia >1.00 DCross-sectional; 6–59 mo; N = 949; amblyogenic risk factors: 20% (192/949); higher-magnitude amblyogenic risk factors: 9% (88/939)Public health and pediatric clinics, United States, orthoptist or pediatrician
Rogers et al52 (2008)MTI photoscreener; SureSight autorefractor
A, SureSight manufacturer referral criteria (hyperopia >2.00 D, myopia >1.00 D, cylinder >1.00 D, or difference >1.00 D); B, SureSight 90% VIP specificity referral criteria (≥4.00, ≥1.00, ≥1.50, or ≥3.00); C, SureSight 94% VIP specificity referral criteria (≥4.25, ≥1.00, ≥1.75, ≥3.50); D, SureSight Rowatt et al87 referral criteria (≥4.25, ≥1.00, ≥2.20, ≥3.00); E, MTI gold-standard referral criteria (≥3.50, >3.00, >1.50, >1.00)
Comprehensive eye examination with cycloplegic refractionAnisometropia >1.5 D; hyperopia >3.50 D; myopia >3.00 D; media opacity >1 mm; astigmatism >1.5 D at 90° or 180° or >1.0 D in oblique axis; ptosis ≤1-mm margin reflex distance; visual acuity per age-appropriate standards; manifest strabismusRCT; 1–6 y; N = 100; clinically significant amblyopia: 58% (58/100)Pediatric ophthalmology clinic, United States, trained layperson
Shallo-Hoffmann et al53 (2004)Lea symbol and HOTV charts, and random dot E stereoacuity test
Required to pass threshold for 1 visual acuity test (Lea symbol chart: correct identification of 4 of 5 symbols on the passing line for age; HOTV chart: all or 1 less than all of the optotypes on the passing line for age), and stereoacuity test (random dot E test: 4 of 5 correct responses)
Comprehensive eye examination with cycloplegic refraction2–3 y; isometropia: myopia ≥3.00 D, hyperopia ≥4.50 D, hyperopia with esotropia >1.50 D, astigmatism >2.00 D; anisometropia: myopia ≥2.00 D, hyperopia ≥1.50 D, astigmatism ≥2.00 D; 3–5 y; isometropia: myopia ≥3.00 D, hyperopia ≥3.50 D, hyperopia with esotropia >1.00 D, astigmatism >1.50 D; anisometropia: myopia ≥2.00 D, hyperopia ≥1.00 D, astigmatism ≥1.50 D; any age; intermittent or constant strabismus; 2-line difference in monocular visual acuities in association with monocular strabismus or amblyogenic refractive error; any pathologyCross-sectional; 2–6 y; N = 269; any vision condition: 6% (5/81)Pediatric ophthalmology clinic, United States (mostly attendees at Caribbean-American preschool and children of indigent Spanish-speaking farmworkers), screener not described
Tong et al56 (2000)MTI photoscreener
Abnormal external examination, media opacity, strabismus, or refractive error (hyperopia ≥2.0 D, myopia ≥2.0 D, anisometropia ≥2.0 D, astigmatism ≥2.0 D)
Comprehensive eye examination with cycloplegic refractionNot describedCross-sectional; <4 y old; N = 387; strabismus: 49% (190/387); refractive error: 55% (211/387)Pediatric ophthalmology clinic, United States, screener not described
VIP Study Group55 (2004)Crowded linear Lea symbols and linear HOTV visual acuity tests
A, 10/32 for age 3 y, 10/20 for age 4 or 5 y; B, 10/32 for age 3 y, 10/25 for age 4 y, 10/20 for age 5 y
Random dot E stereoacuity test
A, nonstereo card for age 3 y, stereo card at 50 cm for age 4 y, stereo card at 100 cm for age 5 y; B, nonstereo card for age 3 or 4 y, stereo card at 50 cm for age 5 y
Stereo Smile II stereoacuity test
A, 240-arc s card for age 3 or 4 y, 120-arc s card for age 5 y; B, 480-arc s card for age 3 or 4 y, 240-arc s card for age 5 y
Retinomax autorefractor
A, hyperopia ≥1.50 D, myopia ≥2.75 D, astigmatism ≥1.50 D, anisometropia ≥2.00 D (year 1) or ≥1.75 D (year 2); B, hyperopia ≥1.75 D (year 1) or ≥2.50 (year 2), myopia ≥2.75 D, astigmatism ≥2.00 D (year 1) or ≥1.75 D (year 2), anisometropia ≥2.75 D (year 1) or ≥2.50 D (year 2)
SureSight autorefractor
A1, manufacturer criteria: hyperopia ≥2.00 D, myopia >1.00 D, astigmatism >1.00 D, anisometropia >1.00 D SE; A2, VIP criteria: hyperopia ≥4.00 D, myopia ≥1.00 D, astigmatism ≥1.50 D, anisometropia ≥3.00 D; B, VIP criteria: hyperopia ≥4.25 D, myopia ≥1.00 D, astigmatism ≥1.75 D, anisometropia ≥3.50 D
iScreen photoscreener
As specified by manufacturer or interpreter of iPower photoscreener
MTI photoscreener
As specified by manufacturer or interpreter of MTI photoscreener
Power Refractor II
A, hyperopia ≥3.50 D, myopia ≥3.00 D, astigmatism ≥2.00 D, anisometropia ≥1.50 D; B, hyperopia ≥5.00 D, myopia ≥3.75 D, astigmatism ≥2.25 D, anisometropia ≥2.75 D
Cover-uncover test
Heterotropia
Comprehensive eye examination with cycloplegic refractionAmblyopia: ≥2-line interocular difference in visual acuity and unilateral amblyogenic factor; or visual acuity worse than 20/50 (3 y old) or 20/40 (4–5 y old) in 1 eye, worse than 20/40 (20/30) in contralateral eye, and bilateral amblyogenic factor; reduced visual acuity: worse than 20/50 (20/40) in 1 eye, worse than 20/40 (20/30) in contralateral eye, and no bilateral amblyogenic factor; or worse than 20/50 (20/40) in 1 eye or ≥2-line difference between eyes (except 20/16 and 20/25), and no unilateral amblyogenic factor; strabismus; significant refractive error: astigmatism >1.50 D, hyperopia >3.25 D, myopia >2.00 D, anisometropia (interocular difference >1.00 D for hyperopia, >3.00 for myopia, >1.50 D for astigmatism, anisometropia (defined)Cross-sectional; 3, 4, or 5 y; N = 3121; any target vision condition: 29% (755/2588); “very important to detect and treat early” conditions: 5.4% (135/2588); amblyopia: 2.9% (75/2588); reduced visual acuity: 5.1% (132/2588); strabismus: 1.9% (48/2588); refractive error: 9.3% (240/2588)Customized Head Start screening vans
Weinand et al57 (1998)MTI photoscreener
Crescent at least half the pupil diameter, asymmetry of light reflexes, or organic abnormalities
Comprehensive eye examination with cycloplegic refractionRefractive error ≥2 D; manifest strabismus; any organic anomalyCross-sectional; 6–18 mo; N = 112; any abnormality: 81% (83/102); refractive error: 41% (41/102); strabismus without refractive error: 7% (7/102); strabismus with refractive error: 21% (21/102); organic anomaly: 13% (13/102)Pediatric ophthalmology clinic, Germany, screener not described
Williams et al58 (2000)Topcon PR2000 autorefractor
Various cutoffs evaluated, cutoffs not predefined
Comprehensive eye examination with cycloplegic refractionSpherical error >3.75 D; anisometropia >1.25 D; astigmatism >1.25 DCross-sectional; 12–69 mo; N = 222; A, spherical error, >3.75 D: 19% (36/189); B, anisometropia, >1.25 D: 12% (23/189); C, astigmatism, >1.25 D: 16% (30/189)Pediatric ophthalmology clinic, United Kingdom, orthoptist
  • NTU indicates National Taiwan University; TNO, a Dutch stereoacuity test.