Friday, July 25, 2014
Eye and Vision Care
Optic nerve damage
My grandson is 8 months old and on his MRI showed signs of optic nerve damage. What could have caused this?
Many things can cause damage to the optic nerve and without examining the child it is impossible to say for sure what is the cause of the nerve damage. Pressure on the nerve from fluid or other structures pushing on the nerve could be a cause. Because you do not mention any other problems seen on the MRI, then I might assume they were not present.
A relatively frequent cause of optic nerve abnormality at birth is optic nerve hypoplasia. In this condition, the nerve is smaller than normal because it does not contain as many fibers as it should. We do not know if the fibers never formed or if they formed and degenerated before birth. The smaller nerve can be seen with an ophthalmoscope or with MRI.
The cause of hypoplasia is unknown. Some contributing factors are young maternal age, use of anticonvulsant drugs during pregnancy, alcohol use during gestation, and maternal diabetes mellitus.
The affect on vision will depend on how many fibers are lost and from where on the retina the fibers are lost (e.g., from central vision or from peripheral field).
Michael Earley, OD, PhD, FAAO
Assistant Dean for Clinical Services
Professor of Clinical Optometry
College of Optometry
The Ohio State University