Optic Nerve Hyperplasia (ONH)
also known as de Morsier’s Syndrome or septo-optic dysplasia
PART OF THE VISUAL SYSTEM AFFECTED- underdevelopment of the optic
nerve(s).
 The visual system of the brain develops according to the visual input it receives
in early childhood. The brain adapts to the small optic nerves, and a child with
ONH may have dramatically better vision at age 5 than they had at age 1.
 Once a child reaches age 8 or so, even if new optic nerves could be generated
by some miraculous procedure, their brain would not process visual input
correctly for normal sight.
DESCRIPTION Small optic disc; sometimes surrounded by a double ring (sclera halo) and
often a pigment epithelium halo
 Vision may be reduced
 Visual acuity can range from no light perception to near-normal vision
EFFECTS ON THE CONDITION OF THE VISUAL SYSTEM Children diagnosed with ONH generally present with vision problems,
involving nystagmus (involuntary movement of the eyes), usually at 1 to 3
months and/or strabismus (inability to align both eyes simultaneously),
during their first year of life.
 Some people experience improvement in vision during the first few years of
life, although the reason is unknown.
 ONH is the SINGLE leading cause of blindness and visual impairment in
children.
 ONH includes agenesis (absence) or abnormal development of the corpus
callosum and septum pellucidum. These abnormalities can be minor and not
cause abnormal brain functions or the brain function can be affected ranging
from mild to severe.
 The areas that can be affected involve gross and fine motor skills; intelligence,
speech and interacting with people and in some people these abnormalities
cause seizures.
COMMON TREATMENTS There is no specific treatment for ONH
 Many therapeutic interventions exist for the care of its symptoms including
hormonal replacement therapy for hypopituitarism, textured food,
occupational, physical, and/or speech therapy.
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
Some other treatments of vision problems may include patching of the better
eye, which may result in improved vision in the worse eye;
MEDICATIONS Growth Hormones
SURGERIES Surgical correction of strabismus should be used for children with symmetrical
functional vision in both eyes.
FUTURE DIRECTIONS The visual prognosis in optic nerve hypoplasia is quite variable.
 Occasionally, optic nerve hypoplasia may be compatible with near-normal
vision; in other cases, one or both eyes may be functionally, or legally blind.
CONGENITAL OR ADVENTITIOUS- congenital abnormality
PROGRESSIVE OR STABLE- stable
ANTICIPATED FUNCTIONAL IMPLICATIONS This condition involves multiple systemic problems stemming from miswiring
of the brain and central nervous system, which manifests in the optic nerves,
especially the hypothalamus.
 Children can have abnormalities in the structure of the brain, its function, or
both.
 All children with ONH are at risk for developmental delays, hormonal
deficiencies, developmental delays, and other challenges. Many of these
challenges include difficulties with sensory integration, motor planning,
intelligence and academic skills, speech and language, and higher order
communication and social skills. Delays in areas such as adaptive functioning,
social skills, and gross and fine motor skills are very typical, and global
developmental delays are also prevalent.
 Children and adults with ONH demonstrate a full range of intellectual
functioning from mental retardation to high intelligence.
 Many children with ONH demonstrate autistic characteristics and some have
behaviors that qualify them for a diagnosis on the Autism Spectrum by a
psychologist or another professional qualified to diagnose behavioral disorders.
 A child with ONH might have difficulty maintaining appropriate social
interactions, rigid adherence to routines, and perseveration (talking
excessively) on a specific and narrowly defined topic of interest.
 Music is often a powerful motivator or even a primary means of
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communication for children with ONH.
REFERENCESCassin, B., Rubin, M.L. (2006). Dictionary of Eye Terminology. (5th Edition). Florida:
Triad Publishing Company.
ONH Consulting. (2010, September 1). Optic Nerve Hypoplasia, Retrieved June 30,
2011 from http://www.tsbvi.edu/seehear/summer06/onh.htm
Rassmussen, Inc. (2005, October 28). Knowledge Process
Outsourcing in Asia, Retrieved July 20, 2007 from
http://www.rassmussen.com/papers/kpoindia.pdf
One Small Voice Foundation. Retrieved July 2, 2011 from
http://www.onesmallvoicefoundation.org/science_onh.html
The Doumas Family: Retrieved July 2, 2011 from
http://www.mindspring.com/~doumas/vision.htm
Developed by LeAundra Ottmo