Optic Nerve Hypoplasia

Presented by :

Julie Greenlee

Angela Howe

What is Optic Nerve Hypoplasia?

Optic Nerve Hypoplasia (ONH) refers to the underdevelopment of the optic nerve during pregnancy.

Some people with ONH also have an abnormal brain and a poorly functioning pituitary gland.

opticnerves

pituitarygland

brain

ONH Characteristics

A wide spectrum of visual funtions ranging from normal visual acuity to no light perceptionj.

Visual field may range from very subtle field loss to depressed visual field

A high percentage of children with ONH have nystagmaus

ONH is not progressive, inherited and can not be cured A mild improvement in visual function may occur with

maturation Mild light sensitivity may occur

Diagnosis by a Docotor

An eye doctor (ophthalmologist) can diagnose optic nerve hypoplasia by looking inside the eye with an ophthalmoscope. The front surface of the optic nerve (optic disc) appears smaller than normal.

With several different exams the doctor may also be able to determine the child’s vision loss.

normaloptic disc

smalloptic disc

Other Health Conditions

There are several other conditions that can occur with ONH. The student can have all, some or none of the following conditions.

Abnormalities of the brain Pituitary glands problems Thyroid gland problems Adrenal gland problems Reproductive organ difficulties

Brain Abnormalities

ONH brain abnormalities can be functional or structural

Persons with septo-optic dysplasia or DeMorsier’s syndrome have a problem with the formation of the septum pellucidum

Other may have an abnormal corpus callosum Others may have abnormally formed different parts

of the brain Malformations can be seen through a CT scan or an

MRI

Pituitary Gland &

Growth Hormone

The Pituitary gland is located at the base of the brain and is responsible for the making of many hormones

When a person has problems making hormones in the pituitary gland it is called hypopituitarism

Growth hormone is made in the pituitary gland and controls bone growth

Lack of growth hormone can cause slower than normal bone growth

Thyroid Gland &

Adrenal Glands

The thyroid glands are located in the neck and produce the thyroid hormone, which helps with growth and energy

Lack of thyroid hormone can lead to poor growth, slowing of mental and muscle function, weight gain, feeling cold, irregular periods (menstrual cycle), hair loss, hoarse voice, brittle nails, and dry, coarse skin.

The adrenal glands are located just above the kidneys and are responsible for producing cortisol.

Cortisol is created during physical activity to help with energy and blood sugar levels

Hypoglycemia &

Anti-Diuretic Hormone

Hypiglycemia is also know as low blood sugar. This can be caused by growth hormone and or cortisol.

If the sugar level is low a person might feel tired, pale, sweaty, confused, be unable to think, to use their muscles well, or have a fast heart beat. If the blood sugar is very low the person might pass out, become unconscious or have a seizure

The pituitary produces a hormone called ADH that is responsible for keeping water in the body by controlling the amount of urine that is created.

Without ADH the person feels very thirsty, has a dry mouth and yet continues to make large amounts of urine.

Sex Hormones&

Prolactin

The pituitary gland produces 2 hormones, FSH- follicle stimulating hormone; and LHLeutinizing hormone, signal the sex glands to produce sex hormaones

Without these hormones, a person’s sexual development is delayed, a girl’s periods are absent or irregular, and it is difficult to father a child or become pregnant.

Prolactin is another hormone made in the pituitary gland. Children with ONH often have abnormal levels of prolactin in their blood.

This leads to no known health problems, but it is often measured by the endocrinologist to test pituitary function.

Treatments

There are no treatments for ONH There are medications for hormonal deficits

that can be prescribed by a docotor.

Educational Impact

The student will require some medical monitoring as well as educational assessment

Depending on visual impairment increase or deccrease font to meet needs of acuity and/or visual field

Will likely need an O&M evaluation

Case study for OPN

Born with hydrocephalus had stunt put in immediately

Other testing to determine effects showed septo-optic dyplasia which causes hypopituitarism and optic nerve hypoplasia

His optic nerve was determined to be “miniscule”- smallest they can be without being absent

Case study contined

With age other problems arise like no production of cortisol, seizure activity, stunt replacement, reduced vision began to patch and wear glasses

At birth told he would have no vision due to his small optic nerve at six he can see 3 to 10 feet and no field vision

Therapist include vision therapist, physical therapist, occupational

therapist, speech therapist, play therapist

Currently is special classes in public school. Continues to make gains with all of his support in his development

Resources

Video of project to raise money for ONH http://www.onesmallvoicefoundation.org/video_loveisblind.html

ONH news report – great explanation http://www.onesmallvoicefoundation.org/video_kttv031505.html

Video student with multiple issues http://www.onesmallvoicefoundation.org/video_wgn032802.html

Guide for ONH in Spanish http://www.onesmallvoicefoundation.org/pdfs/hno_espanol.pdf

References

Bishop, V.E. (2005) Teaching visually impaired children. Springfield, IL: Charles C. Smith.

Kaufman, F. R. , Kaufman, N., Borchert, M., Inlender, T. (June 22, 2007) . Optic nerve hyperplasia (ONH)- General information. Retrieved July 3, 2007, from

http://www.magicfoundation.org/www/docs/101.116/opticnerve-hypoplasia.htmlKaufman, F. R. , Kaufman, N., Borchert, M., Inlender, T. (nd) Optic nerve hypoplasia a

guide for parents. Rertrieved July 14, 2007, from http://www.onesmallvoicefoundation.org/images/ONH%20pamphlet_sm.pdfLeguire, L. E. (nd) Optic nerve hyperplasia (ONH). Retrieved July 3, 2007 from http://ohiolionseyeresearch.com/on_hypoplasia.htm Pediatric visual diagnosis fact sheet (January 1998) Optic nerve hyperplasia.

Retrieved July 3, 2007, from http://www.blindbabies.org/factsheet_onh.htmVerderber, L. (nd). The doctor is in: Optic nerve hypoplasia. Retrieved July 3, 2007,

from http://www.nfb.org/Images/nfb/Publications/fr/fr1/optic.htm