optic chiasma vs optic chiasm

optic chiasma and optic chiasm both are nouns.

Word	Noun	Adjective	Verb	Adverb
optic chiasma	Yes	No	No	No
optic chiasm	Yes	No	No	No

As nouns, optic chiasma and optic chiasm are synonyms defined as:

optic chiasma and optic chiasm: the crossing of the optic nerves from the two eyes at the base of the brain

Other synonyms of optic chiasma include chiasma opticum.

optic chiasma (noun)	optic chiasm (noun)
the crossing of the optic nerves from the two eyes at the base of the brain	the crossing of the optic nerves from the two eyes at the base of the brain