opthalmology for pediatricians
TRANSCRIPT
Ophthalmology for Pediatricians
Dr. Riyad Banayot
Background
Vision Disorders:
Fourth most common disability of childhood
Strabismus 3-4%
Amblyopia 2-3%
Refractive error 15-30%
Amblyopia
Failure to develop normal visual acuity that
Cannot be attributed directly to the effect of any structural
abnormality of the eye or the posterior visual pathway
Types: - Strabismus (misalignment)
- Anisometropia (unequal refractive error)
- Deprivation (media opacity)
Nearly all preventable or reversible with appropriate
intervention
Amblyopia
Most common cause of monocular
blindness in pediatric population
Responsible for more unilaterally
reduced vision of childhood onset than
all other causes combined
Normal Development
Eye of term neonate is 1/3 of adult size
75% of infants are hyperopic (farsighted)
30% have astigmatism (refractive power not
uniform in all areas of cornea)
Immature fovea - limited acuity and fine color
Normal Development
Acuity at birth is 6/120
Age 6 months V/A is 6/6
Color vision improves by 3 months
Eye color evolves by 9-12 months
Iris is lightest in color at birth
Neuroanatomy
LGN synthesizes input
from both eyes
Lack of input from one
eye can damage stereo
vision and acuity
(binocular vision)
“Critical Period”
Critical Period“Period” early
in infancy when the visual system is sensitive to deprivation
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% Vision
Critical Period1st phase:
- Birth to 10 months
- Rapid development
- Highly susceptible to insult
- Responsive to treatment
2nd phase:
- 1 – 9 yrs
- Slower change
- Rehabilitation prognosis poorer
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0 0.5 1 2 3 4 5 6 7 8 9 10Age (yrs)
% Vision
Critical Period
Congenital cataracts must be detected
and removed early !
Early surgery has better prognosis
Age Appropriate Screening
American Academy of Pediatricians (AAP)
AAP Screening Guidelines:
Timing of Exam:
“Age-appropriate” screen at all visits, starting in newborns
Formal ophthalmologic examination for all infants at-risk
Formal screening evaluation starting at age 3 - 4 years
High Risk for Amblyopia
BW < 2000 g (prevalence 20%)
Developmental Delay (TORCH, Down
Syndrome, idiopathic)
Parent or older sibling with amblyopia
Need Eye Exam Before Age 1 year
AAP Screening Guidelines:
History:
“Does your child seem to see well?”
“Does your child seem to hold objects unusually close to face?”
“Do the eyes seem cross?”
AAP Screening Guidelines:
Vision Charts:
3-4 years: Picture tests
> 4 years: Snellen letters or numbers,
tumbling E, letter-matching test
SnellenSnellen
Tumbling ETumbling E
AAP Screening Guidelines:
Birth to 2 Years of Age
Eyelids and orbits
External examination
Motility
Eye muscle balance
Pupils and Red Reflex
Congenital Glaucoma
Congenital Glaucoma:Note larger right corneal diameter
Congenital Glaucoma
Congenital Glaucoma:Note larger right corneal diameter
Congenital Cataract
Corneal Light Reflex
Normal
Corneal Light Reflex
Esotropia
Corneal Light Reflex
Exotropia
Corneal Light Reflex
Hypertropia
Ocular Misalignment
Can be physiologic in first 4 months of life, but usually resolves by 2 months
Newborns can have disconjugate eye movements
Early treatment for strabismus
Must be corrected before age 2 for stereo vision to develop
Pseudostrabismus
AAP Screening Guidelines:
2 years to 4 years
Same as “birth to 2 yrs”
Also should try vision testing
If unable to assess, should refer to
pediatric ophthalmologist
AAP Screening Guidelines:
5 years and older
Formal vision testing
If unable to assess after 2 attempts or
if abnormality found should refer to
ophthalmologist
AAP Screening Guidelines:
Muscle Imbalance Testing
Strabismus, manifest or latent
imbalance of extraocular muscles
Manifest = “Tropia”
Latent = “Phoria”
AAP Screening Guidelines:
Muscle Imbalance Testing
Inward (nasal) = “Eso”
Outward (temporal) = “Exo”
Vertical = “Hyper”
AAP Screening Guidelines:
Muscle Imbalance Testing
“E” = esophoria
“ET” = esotropia
“X” = exophoria
“XT” = exotropia
“H” = hyperphoria
“HT” = hypertropia
Cover / uncover test
Refractive ErrorsAffects 20% of population before late teens
Myopia (nearsighted) common
Hyperopia (farsighted)
Astigmatism - unequal curvature of refractive surface
Anisometropia - unequal refractive errors in each eye
All can possibly cause amblyopia if untreated
Treatment
Correct underlying cause (cataract, strabismus, refractive error)
Strabismus corrected surgically
For amblyopia due to non-surgical causes, treatment is usually with “Occlusion Therapy”
Patch vs. AtropineProspective randomized trial by National
Eye Institute
Early difference at 3 months favoring patch
No difference at 6 months
Atropine accepted better by parents
No known long-term effect of atropine, i.e.
no “reverse amblyopia”
Take Home Message:
Vision disturbances are common
Amblyopia is bad but preventable
Amblyopia can be due to refractive error, strabismus, or other causes
Exam should be age-appropriate
High-risk babies need early care
When in doubt, refer!