Optic Nerve Flashcards
optic nerve is embryologically derived from the ___
optic stalk
total and interval lengths of optic nerve and segments
35-55 mm
intraocular: 0.7-1.0
intraorbital: 25-30
intracanalicular: 4-10
intracranial: 10
optic nerve cells responsible for myelin formation
oligodendrocytes (recall: Scwann cells for peripheral nerves, oligos for CNS)
typical location of optic nerve head coloboma?
inferonasal
cell bodies of optic nerve axons arise from ___
ganglion cell layer of retina
where do the central retinal artery and vein enter the optic nerve
10-15 mm posterior to globe
patchy, transmural granulomatous inflammation of posterior ciliary artery vessel walls causing vascular occlusion and liquefactive necrosis of the optic nerve?
GCA
percentage of patients with sarcoid who have ocular or orbital involvement
35%
classic, “naked” (not surrounded by lymphocytes), non-caseating granulomas
sarcoidosis (although, ranulomas of optic nerve may feature necrosis)
vacuolar alteration of optic nerve axons, lateral displacement of retinal, juxtapapillary serous intraretinal fluid
optic disc edema
large, cystic spaces in ON posterior to lamina cribrosa which contain mucopolysaccharide that stains with alcian blue?
Schnabel’s cavernous optic atrophy
Widened subdural space around optic nerve is a sign of ___
optic atrophy
Deeply pigmented tumor situated eccentrically on optic disc of white woman?
melanocytoma (benign)
Systemic disorder commonly associated with optic nerve glioma (astrocytoma)? Characteristic eosinophilic filaments?
NF1. Rosenthal fibers.
from which layer do primary optic nerve sheath meningiomas arise?
arachnoid sheath
