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Spring 99 Table of Contents
Versión Español de este artículo (Spanish Version)
Reprinted with permission from Blind Babies Foundation
Optic Nerve Atrophy (ONA) is a permanent visual impairment caused by damage to the optic nerve. The optic nerve functions like a cable carrying information from the eye to be processed by the brain. The optic nerve is comprised of over a million small nerve fibers (axons). When some of these nerve fibers are damaged through disease, the brain doesn't receive complete vision information and sight becomes blurred. Atrophy (wasting away) may be partial in which some axons are damaged or profound in which most axons are damaged. A child's ability to see clearly (visual acuity) is affected due to nerve damage that occurs in the central part of the retina responsible for detail and color vision (macula). These areas of the eye are more vulnerable to the effects of atrophy. ONA is the end result of damage to the optic nerve. It can affect one or both eyes. It may also be progressive, depending on the cause.
Many diseases and conditions may lead to optic atrophy. Tumors of the visual pathways, inadequate blood or oxygen supply (hypoxia ischemia) before or shortly after birth, trauma, hydrocephalus, heredity, and rare degenerative diseases have been identified as causes of ONA. When hereditary, the pattern is dominant. This means that one parent with the condition would pass the gene to 50% of his/her children. If caused by a tumor, the process of ONA may be halted by removal of the tumor.
ONA in children is diagnosed by a pediatric ophthalmologist in a number of ways, including:
Although there are several types of ONA, the following characteristics are common to most:
The following statement is NOT TRUE according to current research:
Ongoing evaluation, and communication among family, medical and education specialists is essential to develop the best home and school program for the child with ONA. Assessment and services from a pediatric ophthalmologist, a teacher of the visually impaired, and a specialist in Orientation and Mobility who keep in close communication with caregivers will ensure maximum development for the child.
Axon: single projection from a nerve cell that under normal conditions, carries nerve impulses away from the cell body.
Optic Nerve Hypoplasia: refers to underdevelopment of the optic nerve during pregnancy.
(1986). Eye Facts about Optic Atrophy, American Academy of Ophthalmology.
Hoyt, C., Good, W. (1992). Do We Really Understand the Difference Between Optic Nerve Hypoplasia and Atrophy?, Eye, 6, 201-204.
Kjer, P. (1959). Infantile Optic Atrophy With Dominant Mode of Inheritance, ACTA OPHTHALMOLOGICA, Sept., 23.
Mantyjarvi, M., Nerdrum, K., Tuppurainen, K. (1992). Color Vision in Dominant Optic Atrophy, Journal of Clinical Neuro-ophthalmology, 12(2), 98-103.
McGinnity, F.G., Bryars, J.H. (1992). Controlled study of ocular morbidity in school children born preterm, British Journal of Ophthalmology, 76, 520-524.
Menon, V., Arya, A., Sharma, P., Chhabra, V.K. (1992). An aetiological profile of optic atrophy, ACTA OPHTHALMOLOGICA, 70, 725-729.
Miki, A., Nakajima, T., Takagi, M., Shirakashi, M., & Abe, H. (1996). Detection of Visual Dysfunction in Optic Atrophy by Functional Magnetic Resonance Imaging During Monocular Visual Stimulation, American Journal of Ophthalmology, 122, 404-415.
Tuppurainen, K., Herrgard, E., Martikainen, A., Mantyjarvi, M. (1993). Ocular findings in prematurely born children at 5 years of age, Graefe's Arc Clin Exp Ophthalmol, 231, 261-266.
Project Coordinators: Julie Bernas-Pierce, M.Ed. Dr. William Good, Hsiao-hui Ning, Dennak Murphy, Linda Kekelis, Sandra Nevin, Susana Saeidnia. Reviewers: Dr. William Good, Kathryn Neale Manalo.
The Pediatric Visual Diagnosis Fact Sheets are sponsored by a grant from the Blind Childrens Center and with support from the Hilton/Perkins Program through a grant from the Conrad Hilton Foundation of Reno, Nevada. REPRODUCTION FOR RESALE IS STRICTLY PROHIBITED (1/98 BBF)
Blind Babies Foundation
1200 Gough Street
San Francisco, California 94109
Editor's note: Blind Babies Foundation has developed 7 Pediatric Visual Diagnosis Fact SheetsTM on the following topics: Cortical Visual Impairment, Retinopathy of Prematurity, Optic Nerve Hypoplasia, Albinism, Optic Nerve Atrophy, Retinal Diseases, and Vision Assessment. One complete set costs $10. Families can get one Fact Sheet free of charge upon request. The Blind Childrens Center will have the Fact Sheets available soon on their website at www.blindcntr.org/bbc.
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Last Revision: October 31, 2005