Paeds · ophthalmology
Visual development, amblyopia and vision screening in childhood
Also known as Amblyopia · Lazy eye · Childhood vision screening · Patching for amblyopia · Strabismic and anisometropic amblyopia
Fellowship guide to visual development, amblyopia and vision screening in childhood: the maturation of acuity from newborn 6/60 toward adult 6/6 across a sensitive period to about 7 to 9 years; amblyopia as a unilateral, rarely bilateral, cortical reduction in best-corrected acuity from abnormal visual experience in that window, classified as strabismic, anisometropic, stimulus-deprivation or bilateral ametropic; the cortical mechanism of suppression and reorganisation of ocular dominance columns that lets amblyopia both develop and be treated; the age-based screening programme from the newborn red reflex, through instrument photoscreening at 1 to 3 years, to monocular acuity at 4 to 5 years with the refer threshold of 0.2 logMAR or worse or a two-line interocular difference; and the management ladder of refractive correction first, then occlusion of the better eye two to six hours a day or atropine one per cent penalisation, supported by the PEDIG trials showing equivalence of two and six hours of patching and of atropine and patching for moderate amblyopia, with urgent referral of the red flags of leukocoria and absent red reflex.
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Red flags
- A white pupil, leukocoria or an absent or asymmetric red reflex in an infant is congenital cataract or retinoblastoma until proven otherwise and needs urgent same-day ophthalmology referral, because deprivation amblyopia closes the sensitive period fastest and a missed retinoblastoma is a missed life-threatening diagnosis
- A new manifest strabismus persisting beyond four months of age is not a normal variant; it needs ophthalmology assessment, because suppression of the deviating eye sets up strabismic amblyopia within the sensitive period
- A child who passes a casual both-eyes-open check can still have severe unilateral amblyopia, because suppression hides the poorer eye; only monocular acuity testing, each eye separately, will reveal it
- Untreated unilateral amblyopia leaves the child dependent on a single seeing eye for life, and the chief population-level risk is later loss or injury to that good eye, which is the justification for universal preschool screening
Life stages
Care settings
Clinical exam formats
Board mappings
- Ophthalmology
- Visual development and vision screening in childhood
- Amblyopia and strabismus
- General Paediatrics learning goal — recognise, screen for and initiate management of amblyopia, and refer deprivation causes and red flags urgently
- Perform age-appropriate vision screening from red reflex to monocular acuity and apply the refer thresholds
- Stepwise management of amblyopia: refractive correction, occlusion or atropine penalisation, with ophthalmology shared care
- Child development and behaviour
- Clinical Applications — vision screening and amblyopia
- Short Cases
- Long Cases
- Communication scenarios
- Ophthalmology: recognises and manages common visual problems in children including amblyopia and strabismus
- Vision screening across the preschool and school-age years
- Red flags in the paediatric eye examination
- Foundation of Practice (FOP)
- Applied Knowledge in Practice (AKP)
- Amblyopia, strabismus, refractive error and vision screening
- Clinical
- History
- Communication
- Eye examination and vision screening
- General Pediatrics Content Outline — Ophthalmology
- Vision screening and amblyopia
- Strabismus, refractive error and the red reflex
- Patient Care 1: History and Physical Examination
- Patient Care 4: Clinical Reasoning
- Medical Knowledge 1: Clinical Knowledge of paediatric visual development and amblyopia
- Systems-Based Practice 1: vision screening programmes and specialist referral
- Medical Expert
- Collaborator
- Pediatrics: Core EPA — vision screening and amblyopia
Overview & Definition
Picture a four-year-old who sailed through her newborn and infant checks and sees perfectly with both eyes open, but who, at her school-entry vision test, can read only the top line with her left eye when the right is covered. The eye looks completely normal, there is no turn and no white pupil, yet acuity in that eye is poor and does not improve with a pinhole. This is amblyopia, and the key idea is that the problem is in the brain, not the eye: during the sensitive period of visual development the cortex received a blurred or competing image from that eye and learned to suppress it, so the neural machinery for sharp vision never developed. [2]
Normal visual development is a race against a closing window. A newborn sees at roughly 6/60 and refines acuity steadily through infancy and early childhood toward the adult 6/6, building the cortical circuits and binocular connections that depend on two clear, well-aligned images. That construction is most plastic in the first two to three years and tapers over the sensitive period to about seven to nine years of age, after which the cortex is much harder to remodel. The same plasticity is the reason amblyopia can be treated at all — forcing the weaker eye to work during the window lets the cortex recover — and the reason that, once the window closes, untreated amblyopia is largely permanent. [1] [11]
Amblyopia is defined as a unilateral, or occasionally bilateral, reduction in best-corrected visual acuity caused by abnormal visual experience during the sensitive period, in the absence of an organic lesion of the eye or visual pathway that would fully explain the deficit. It is common, affecting about one to three per cent of children, which makes it the leading cause of unilateral vision loss in this age group. Crucially, it is invisible to a both-eyes-open check, because the better eye hides the poorer one, so detection depends on testing each eye separately. [2]
References12ShowHide
- [1]Donahue SP, Nixon CN Visual System Assessment in Infants, Children, and Young Adults by Pediatricians. Pediatrics, 2016.PMID 29756730
- [2]Holmes JM, Clarke MP Amblyopia. Lancet, 2006.PMID 16631913
- [3]Wallace DK, Lazar EL, Holmes JM, et al. A randomized trial of increasing patching for amblyopia. Ophthalmology, 2013.PMID 23755872
- [4]Wallace DK, Edwards AR, Cotter SA, et al. A randomized trial to evaluate 2 hours of daily patching for strabismic and anisometropic amblyopia in children. Ophthalmology, 2006.PMID 16751033
- [5]Repka MX, Kraker RT, Holmes JM, et al. Atropine vs patching for treatment of moderate amblyopia: follow-up at 15 years of age of a randomized clinical trial. JAMA Ophthalmol, 2014.PMID 24789375
- [6]Repka MX, Wallace DK, Beck RW, et al. Two-year follow-up of a 6-month randomized trial of atropine vs patching for treatment of moderate amblyopia in children. Arch Ophthalmol, 2005.PMID 15710809
- [7]Solebo AL, Cumberland PM, Rahi JS Whole-population vision screening in children aged 4-5 years to detect amblyopia. Lancet, 2015.PMID 25499167
- [8]Carlton J, Karnon J, Czoski-Murray C, et al. 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.PMID 18513466
- [9]Garry GA, Donahue SP Validation of Spot screening device for amblyopia risk factors. J AAPOS, 2014.PMID 25266832
- [10]Anderson J Don't Miss This! Red Flags in the Pediatric Eye Examination: Abnormal Red Reflex. J Binocul Vis Ocul Motil, 2019.PMID 31329054
- [11]Gopal SKS, Kelkar J, Kelkar A Simplified updates on the pathophysiology and recent developments in the treatment of amblyopia: A review. Indian J Ophthalmol, 2019.PMID 31436180
- [12]Zhang X, Wang J, Li Y, et al. Diagnostic test accuracy of Spot and Plusoptix photoscreeners in detecting amblyogenic risk factors in children: a systemic review and meta-analysis. Ophthalmic Physiol Opt, 2019.PMID 31236980