Optic nerve hypoplasia. Identification by magnetic resonance imaging
M. C. Brodsky, C. M. Glasier, S. C. Pollock and E. J. Angtuago
Department of Ophthalmology, University of Arkansas for Medical Sciences, Little Rock.
High-resolution magnetic resonance images of the intracranial optic nerves
and chiasm were obtained in 15 patients with severe optic nerve hypoplasia.
These were compared, in a double-blind manner, with similar images from 30
age-matched controls. On both coronal and sagittal images, hypoplastic
optic nerves were thin and demonstrated signal attenuation when compared
with normal optic nerves. All patients with severe bilateral optic nerve
hypoplasia also had diffuse chiasmal hypoplasia, which was seen best on
coronal images. Patients with unilateral or asymmetrical optic nerve
hypoplasia had variable chiasmal abnormalities. The degree to which the
magnetic resonance diagnosis of optic nerve hypoplasia matched the clinical
diagnosis was highly significant (P less than .001, Fisher's Exact Test)
for both coronal and sagittal views of the intracranial optic nerves.
Oblique axial and coronal views of the orbital optic nerves did not
reliably distinguish optic nerve hypoplasia from normal optic nerves.
High-resolution magnetic resonance imaging is a useful diagnostic modality
to identify small optic nerves neuroradiologically.
