optic chiasma


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Related to optic chiasma: corpus callosum, optic tract

optic chiasma

[′äp·tik kī′az·mə]
(neuroscience)
The partial decussation of the optic nerves on the undersurface of the hypothalamus.
References in periodicals archive ?
Magnetic resonance (MR) imaging was superior to CT in detecting cavernous sinus invasion, tumour relation to ICA, optic chiasma and in internal characterization of the lesion.
The precise visual field defect caused by a lesion compressing the optic chiasma depends on location of optic chiasma with respect to sella tursica.
7 Hypophysis, stalk, cavernous sinuses, sphenoid sinus and optic chiasma are well evaluated on coronal and sagittal T1-weighted MRI both before and after Gadolinium injection.
6) The optic nerve was called a poros (duct), possibly because of the ophthalmic artery occupying its centre; the origin of the nerve from the floor of the brain (Herophilus' 'centre of intelligence'), its cross-over in the optic chiasma and continuation through the skull to the eyeball, was described.
Enhanced magnetic resonance imaging (MRI) revealed a well defined extra axial solid mass lesion in the anterior cranial fossa about 27x23x26mm causing mass effect over the optic chiasma and also with extension into the right optic canal.
Similarly, optic nerve or optic chiasma damage may cause visual blurring or diplopia.
Bilateral anophthalmos may have an associated absence of the optic chiasma, a diminished size of the posterior pathways, as well as agenesis of the corpus callosum.