Optic Nerve Hypoplasia
Optic Nerve Hypoplasia (ONH) is a
congenital condition characterized by the
under-development or absence of one or
both optic nerves. Since the optic nerve is
responsible for sending visual signals to the
brain, its under-development or absence
can result in significant visual impairment.
Optic Nerve Hypoplasia may occur alone or
in conjunction with other neurological
problems, brain abnormalities,
developmental delay, or endocrine
disorders.
Normal optic nerve head and
retina.
Optic nerve hypoplasia. The small
white spot surrounded by a dark
ring in the center e photo is the
optic nerve. Note the much smaller
size compared to the normal optic
nerve.
Vision impairment in persons with ONH
ranges from near normal to no light
perception in one or both eyes. Physical or
functional abnormalities are also often
present within the structures near the optic
nerve at the midline of the brain. These
include:



hypothalamus -- produces many
important hormones
pituitary gland -- responsible for
functioning of the glands in the
body, including growth
corpus callosum -- separates the
right and left sides of the brain and
is responsible for transferring

information between the two sides
of the brain
septum pellucidum -- a membrane
that separates the lateral ventricles
of the brain. If absent, serious
neurological problems, including
seizures, dysfunction of the
hypothalamus, and problems with
coordination may be present .
Absence of the septum pellosum is
referred to as septo-optic dysplasia.
Early symptoms of optic nerve hypoplasia
may include involuntary eye movements
(nystagmus) where the eyes constantly
move back and forth without focusing on
any object or eyes that do not align
(strabismus). These symptoms commonly
appear in the first years of life.
There is no specific treatment or cure for
this condition, but it is not a progressive
condition. Children should be followed by
an eye doctor and other specialists
(endocrinologists, ophthalmologists,
speech/occupational therapists) as
applicable to the degree of impairment and
presence of complications associated
conditions. Involvement in early
intervention programs is recommended to
reduce the impact of vision loss on general
development. Low vision aids can be used
successfully by some individuals to improve
vision and daily living activities.
Prognosis is variable and depends upon the
degree of optic nerve damage and
associated cerebral malformation.
Expectations for vision are also variable. On
occasion, near-normal vision may be
present while in other cases, one or both
eyes may be functionally, or legally, blind.
Many persons with optic nerve hypoplasia
lead normally productive lives. However,
persons with septo-optic dysplasia may
have numerous non-visual problems as
well.
References:
Blind Babies Foundation. (no date). Optic Nerve Hypoplasia [Brochure]. Retrieved from
http://66.147.244.207/~blindbab/wp-content/uploads/2010/08/Fact-Sheet-Optic-NerveHypoplasia.pdf
Borchert, Mark and Garcia-Filion, Pamela. (2008). http://www.onesmallvoicefoundation.org.
In The Syndrome of Optic Nerve Hypoplasia. Retrieved June 23, 2011, from
www.onesmallvoicefoundation.org/documents/SONHreview.pdf
Children's Hospital of Los Angeles. (no date). Optic Nerve Hypoplasia: A Guide for Parents
[Brochure]. Retrieved from http://www.chla.org/atf/cf/%7B1CB444DF-77C3-4D94-82FAE366D7D6CE04%7D/ONHBookletforParents.pdf
Kaufman, F, Kaufman, N, Borchert, M, & Inlender, T. (June 7, 2011). Optic Nerve Hypoplasia
(ONH)-General Information. In The Magic Foundation. Retrieved June 23, 2011, from
http://www.magicfoundation.org/www/docs/101.116/optic-nerve-hypoplasia-septo-opticdysplasia?enlarged
Leguire, L.E.. (n.d.). Optic Nerve Hypoplasia. In Ohio Lions Eye Research Foundation. Retrieved
June 27, 2011, from http://www.ohiolionseyeresearch.com/on_hypoplasia.htm
[Untitled photograph of a retina]. Retrieved June 29, 2011, from:
http://www.ohiolionseyeresearch.com/on_hypoplasia.htm