Download Module - Mount Sinai Hospital

Early Intervention
Training Center
for Infants and Toddlers With
Visual Impairments
Module:
Visual Conditions and Functional Vision:
Early Intervention Issues
Session 2: Visual Capacity
Handout D: Congenital Structural Abnormalities That May Alter Visual
Development
EIVI Traning Center. (2003). Congenital structural abnormalities that may alter visual
development. Chapel Hill, NC: Early Intervention Training Center for Infants and
Toddlers With Visual Development, FPG Child Development Institute, UNC-CH.
Name
Optic nerve hypoplasia
Source
Elston
(2000)
Comments
 Occurs in the first or early second
trimester
 May be associated with young
maternal age, fetal alcohol
syndrome, possible maternal
diabetes mellitus
 Children at increased risk of
endocrine disturbances
 Visual acuity may range from light
perception to normal acuity
Hertle,
Schaffer, &
Foster
(2002)

Atypical development of the optic
nerve
Microphthalmia/
anophthalmia
Anophthamia, absence of the eye, or
micropthalmia, a very small and
typically malformed eye, represent
structural abnormalities of the globe



Visual Conditions Module 06/04/04
EIVI-FPG Child Development Institute
UNC-CH
May result from insult at number of
developmental stages or from acute
exposure to toxins during early
development
Could be due to failure or late
closure of optic fissure
Microphthalmia may result in
decreased visual acuity,
photophobia, fluctuating visual
abilities
Anophthalmia results in total
blindness of affected eye
S2 Handout D
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Early Intervention
Training Center
for Infants and Toddlers With
Visual Impairments
Name
Colobomas
Source
Comments
Cook, Sulick,  Defect occurs at 4 to 5 weeks’
& Wright
gestation
Failure of parts of the ocular system to (2003)
 Can affect iris, choroid, retina, and
develop due to abnormal fusion of
optic nerve
optic fissure
 When optic nerve and/or retina is
involved, vision is affected.
 Isolated iris colobomas may not
affect visual acuity.
 Decreased visual acuity,
photophobia, field loss often result
from colobomas, depending on area
that failed to develop.
Congenital cataracts
Wright
 May result from genetic/hereditary
(2003)
conditions, maternal infection,
Clouding or opacity of the lens that
systemic diseases
produces indistinct image on retina
 Treatment within the first few weeks
of life results in near-normal visual
development
Developmental abnormalities of the
anterior segment
(Defective development of structures
near the front of the eye—between
cornea and vitreous)
Hertle,
Schaffer, &
Foster
(2002)



Defects in these structures may
result in poor vision due to
obstruction of light as it passes
through the cornea, pupil, or lens
Defects in trabeculum (involved in
circulation/drainage of fluid in the
eyes) can result in primary glaucoma
that can cause vision loss
Defects of iris (aniridia, coloboma)
affect pupil size and can cause
atypical visual development
References
Cook, C., Sulik, K.K., & Wright, K.W. (2003). Embryology. In K.W. Wright & P.H. Spiegel (Eds.),
Pediatric ophthalmology and stabismus (2nd ed., pp. 3-38). New York: Springer.
Elston, J. (2000). Visual pathway disorders. In A. Moore & S. Lightman (Eds.), Fundamentals of
clinical ophthalmology: Paediatric ophthalmology (pp. 223-235). London: BMJ Books.
Hertle, R.W., Schaffer D., & Foster, J. (2002). Pediatric eye disease: Color atlas and synopsis.
New York: McGraw Hill.
Wright, K.W. (2003). Lens abnormalities. In K.W. Wright & P.H. Spiegel (Eds.), Pediatric
ophthalmology and strabismus (2nd ed., pp. 450-480). New York: Springer.
Visual Conditions Module 06/04/04
EIVI-FPG Child Development Institute
UNC-CH
S2 Handout D
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