II. Definitions

  1. Amblyopia
    1. Poor Vision not correctable with eyeglasses developing in early childhood
    2. Greek: "Dullness of Vision"

III. Epidemiology

  1. Prevalence: 2-6% of US Children
  2. Occurs in children up to age 6 years
  3. Most common childhood cause of monocular Vision Loss
  4. Cause of permanent Vision Loss in 2.9% of adults in U.S.

IV. Pathophysiology

  1. Visual blur at level of Retina coinciding with visual development in early childhood
  2. Occurs in developmentally immature eye
    1. During first 6 months of life
    2. Acuity normally improves rapidly 20/400 => 20/80
    3. Eye fully matures by age 9 years
  3. Normal maturity
    1. Requires clear, equal, aligned image for each eye
    2. Conflicting data with
      1. Strabismus (2 competing images)
      2. Anisometropia (1 clear, 1 blurred image)
    3. Brain suppresses information from the "bad" eye in children
      1. Contrast with adults, who are unable to suppress conflicting images and therefore experience Diplopia
    4. Continued suppression leads to permanent Vision Loss
      1. Loss of binocular Vision and depth Perception

V. Causes

  1. Strabismus (most common cause of Amblyopia)
    1. Misalignment of eyes
    2. Eyes are deviated inward or crossed (esotropia) or outward (exotropia)
    3. One eye is suppressed to prevent Diplopia, and disuse results in Amblyopia
  2. Refractive Amblyopia
    1. Isometric Amblyopia (Ametropic Amblyopia)
      1. Severe, equal Refractive Errors (results in bilateral Amblyopia)
    2. Anisometropia
      1. Large difference in Refractive Error between eyes
      2. Causes
        1. Bilateral Hyperopia or far sightedness (most common)
          1. Myopia is less likely to result in Vision Loss
        2. Severe unilateral Hyperopia or Myopia
        3. Astigmatism
        4. Induced Astigmatism
          1. Eyelid Ptosis
          2. Periorbital Capillary Hemangioma
          3. Mild Congenital Cataract
  3. Deprivation Amblyopia or Physical Occlusion (least common)
    1. Congenital Cataract
    2. Retinoblastoma
    3. Corneal scarring
    4. Vitreous opacity
    5. Severe Ptosis
    6. Optic atrophy
    7. Iatrogenic excessive patching

VI. History

  1. Wandering eye
  2. Squinting of one eye (associated with eye wandering or exotropia)
  3. Torticollis (child tilts head to better re-align the eyes, or to decrease Nystagmus)
  4. Nystagmus
  5. Strabismus

VII. Exam

  1. Vision
    1. See Pediatric Vision Screening
  2. Exam for associated ocular disease
    1. Ptosis
    2. Cataracts or Corneal opacities
    3. Pupil exam
    4. Extraocular Movement
  3. Test for eye alignment abnormality (Strabismus)
    1. Corneal Light Reflex
    2. Cover-Uncover exam
    3. Bruckner Test (Red Reflex)
    4. Fixation and following
  4. Differentiate Refractive Error from Amblyopia
    1. Pinhole Test
  5. Photoscreeners
    1. Red Reflex evaluated in digital flash photograph taken of both eyes
    2. Uncorrected Refractive Error can be inferred from the image
    3. Iphone Application (gocheckkids) costs ~$150 per month per phone
    4. Test Sensitivity 65% and Test Specificity 83%
    5. Arnold (2018) Clin Ophthalmol 12:1533-7 [PubMed]
    6. Matta (2009) Arch Ophthalmol 127(12):1591-5 [PubMed]

VIII. Management: Indications to refer to pediatric ophthalmology

  1. Family History
    1. Sibling requiring glasses before age 2.5 years
    2. Amblyopia Family History
    3. Strabismus Family History (esp. parental history, which increases child's risk four fold)
    4. Congenital Cataract Family History
    5. Congenital Glaucoma Family History
  2. Infant Findings
    1. RetinoblastomaFamily History
    2. Abnormal Red Reflex
    3. Abnormal eye tracking after age 3 months
    4. Strabismus
    5. Chronic eye tearing or discharge
    6. Gestational age <30 weeks
    7. Birth weight <1500 g (3 lb 5 oz)
    8. Cerebral Palsy
    9. Down Syndrome and other syndromes with eye involvement
  3. Childhood findings
    1. Strabismus
    2. Ptosis
    3. Age 3.5 to 5 years
      1. Vision worse than 20/40 in either eye
    4. Age >5 years
      1. Vision worse than 20/32 in either eye
      2. Child not reading at grade level

IX. Management

  1. Treat underlying cause early
    1. Address Congenital Cataracts and Refractive Error if present
    2. Correct Strabismus if present
  2. Previously, encouraged children to write or draw while good eye obscured
    1. However near activities have not been found to improve Amblyopia
  3. Force child to use amblyopic eye by obscuring good eye
    1. Approach
      1. Late presenting, older children with more significant Amblyopia typically receive more aggressive approach
        1. Sustained glasses and patching
      2. Patching for 2 hours daily is as effective as 6 hours daily in moderate Amblyopia (20/40 to 20/80)
      3. Patching for 6 hours daily is as effective as 23 hours daily in severe Amblyopia (20/100 to 20/400)
    2. Manual methods
      1. Patch "good", dominant eye (usual course)
      2. Opaque Contact Lenses
      3. Cloth over glasses on good eye side or prescription glasses to blur good eye
        1. However, glasses are less effective since child may still see around the edges of the glasses
      4. Bangter Filter (graded adhesive applied to glasses lens over the good eye)
        1. Indicated in moderate Amblyopia
        2. As effective as 2 hours of patching daily
    3. Atropine (0.5-1%) 1 drop daily for 2-7 days per week
      1. When used on 2 consecutive days per week is as effective as daily use
      2. Daily Atropine is as effective as daily patching in moderate Amblyopia
      3. Indicated in noncompliant children
      4. Most effective in far sightedness
      5. Apply to good eye to dilate pupil
      6. Prevents accommodation and causes Vision blurring

X. Prognosis

  1. Early, aggressive, and consistent therapy is critical
    1. Most responsive before age 3-5 years old
    2. Good outcomes when treated at age <7 years
  2. Amblyopia recurs in 24% after 1 year
    1. Be vigilant about surveillance
  3. Amblyopia nearly irreversible after age 9 years
    1. New studies suggest teens may benefit from therapy
    2. Scheiman (2005) Arch Ophthalmol 123:437-47 [PubMed]

XI. Resources: Patient Education

  1. Information from your Family Doctor
    1. http://www.familydoctor.org/handouts/460.html

Images: Related links to external sites (from Bing)

Related Studies

Ontology: Amblyopia (C0002418)

Definition (MSHCZE) Tupozrakost. Při tupozrakosti je zraková ostrost snížená, aniž se na příslušném oku nalezne zřetelný organický nález (poškození). Jde v podstatě o funkční poruchu, která vzniká bezděčným potlačováním vjemu z oka, pokud by jeho vnímání rušilo celkový zrakový vjem. K tomu dochází např. při šilhání - strabismu. A. vzniká často již v raném dětství, kdy se však zároveň dá nejlépe léčit a odstranit její příčina. (cit. Velký lékařský slovník online, 2013 http://lekarske.slovniky.cz/ )
Definition (CSP) impairment of vision without detectable organic lesion of the eye.
Definition (MSH) A nonspecific term referring to impaired vision. Major subcategories include stimulus deprivation-induced amblyopia and toxic amblyopia. Stimulus deprivation-induced amblyopia is a developmental disorder of the visual cortex. A discrepancy between visual information received by the visual cortex from each eye results in abnormal cortical development. STRABISMUS and REFRACTIVE ERRORS may cause this condition. Toxic amblyopia is a disorder of the OPTIC NERVE which is associated with ALCOHOLISM, tobacco SMOKING, and other toxins and as an adverse effect of the use of some medications.
Definition (PSY) An optically uncorrectable loss of visual acuity without apparent organic change or defect.
Concepts Finding (T033)
MSH D000550
ICD9 368.00
ICD10 H53.00
SnomedCT 267627009, 155145007, 193637007, 111517004, 267726008, 387742006
LNC LA16299-2
English Amblyopia, Amblyopias, AMBLYOPIA, Amblyopia, unspecified, amblyopia, amblyopia (diagnosis), Amblyopia NOS, Unspecified amblyopia, Amblyopia [Disease/Finding], amblyopic, Unspecified amblyopia (disorder), Amblyopic, Amblyopia (disorder), Amblyopia, NOS
French AMBLYOPIE, Amblyopie, non précisée, Amblyopie SAI, Amblyopie
Portuguese AMBLIOPIA, Ambliopia NE, Olho Vago, Ambliopia
Spanish AMBLIOPIA, Ambliopía no especificada, Ambliopía NEOM, ambliopía no especificada, ambliopía no especificada (trastorno), ambliopía (trastorno), ambliopía, Ambliopía
German AMBLYOPIE, Amblyopie, unspezifisch, Amblyopie NNB, Amblyopie, Schwachsichtigkeit, Sehleistung, herabgesetzte
Dutch amblyopie NAO, amblyopie, niet-gespecificeerd, amblyopie, Amblyopie
Italian Ambliopia NAS, Ambliopia, non specificata, Ambliopia
Japanese 弱視NOS, 弱視、詳細不明, ジャクシショウサイフメイ, ジャクシNOS, ジャクシ, 弱視
Swedish Amblyopi
Czech amblyopie, Tupozrakost, blíže neurčená, Amblyopie, Amblyopie NOS
Finnish Heikkonäköisyys
Polish Niedowidzenie
Hungarian Amblyopia, Amblyopia k.m.n., Amblyopia, nem meghatározott
Norwegian Amblyopi

Ontology: Lazy Eye (C0422955)

Concepts Disease or Syndrome (T047)
MSH D000550
SnomedCT 393714006, 392760001, 246623008
Dutch lui oog, Lui oog
German Lazy eye, Lazy Eye
Italian Occhio ambliopico, Occhio pigro
Portuguese Ambliopia - "olho preguiçoso", Olho Preguiçoso
Spanish Ojo perezoso, Ojo Vago, ojo perezoso (hallazgo), ojo perezoso
Japanese 弱視眼, ジャクシガン
Czech tupozrakost, Lenivé oko
French Oeil paresseux
English Eye, Lazy, Eyes, Lazy, Lazy Eyes, eye lazy, lazy eyes, lazy eye, Lazy eye, Lazy eye (finding), Lazy Eye
Hungarian Tompalátás