Optical coherence tomography (OCT) may also be used to confirm the diagnosis of CRAO. Causes
CRAO can be classified based on it pathogenesis, as arteritic versus non-arteritic. Non-arteritic CRAO is most commonly caused by an embolus and occlusion at the narrowest part of the carotid retinal artery due to plaques in the carotid artery resulting in carotid retinal artery atherosclerosis. Further causes of non-arteritic CRAO may include vasculitis and chronic systemic autoimmune diseases. Arteritic CRAO is most commonly caused by giant cell arteritis. Other causes can include dissecting aneurysms and arterial spasms, and as a complication of patient positioning causing external compression of the eye compressing flow to the central retinal artery (e.g. in spine surgeries in the prone position). Mechanism
The ophthalmic artery branches off into the central retinal artery which travels with the optic nerve until it enters the eye. This central retinal artery provides nutrients to the retina of the eye, more specifically the inner retina and the surface of the optic nerve. Variations, such as branch retinal artery occlusion, can also occur. Central retinal artery occlusion is most often due to emboli blocking the artery and therefore prevents the artery from delivering nutrients to most of the retina. These emboli originate from the carotid arteries most of the time but in 25% of cases, this is due to plaque build-up in the ophthalmic artery. The most frequent site of blockage is at the most narrow part of the artery which is where the artery pierces the dura covering the optic nerve.
As for all other opioid-based medications, naloxone (trade name Narcan) is the definitive antidote for overdose. Depending on the amount administered, it can reverse the respiratory depression and, if enough is administered, completely reverse the effects of sufentanil. See also
Betahydroxythiofentanyl
Carfentanil
R-30490
Thiafentanil

References
External links
"Sufentanil". Drug Information Portal. U.S. National Library of Medicine. "Sufentanil citrate". Drug Information Portal. U.S. National Library of Medicine.