An interesting presentation of ruptured anterior communicating artery aneurysm with acute monocular vision loss
Reviewed by Claire Howard

The authors report an interesting case of a 60-year-old man presenting with acute monocular vision loss accompanied by periorbital pain as an unusual presentation of subarachnoid haemorrhage (SAH) from ruptured anterior communicating artery aneurysm. The patient did not present with any neurological deficit, which is generally the presenting feature for this condition. In addition, changes in mental status are known to occur which, again, was not found for this reported case. A relative afferent pupillary defect was present in the affected eye. As the anterior communicating artery is located close to the optic nerve, aneurysm should be considered when there is presentation of unilateral decrease in visual acuity with periorbital pain, even in the absence of other neurological signs. Other symptoms to look for include transient headache and / or bitemporal or homonymous hemianopia (due to compression of the optic chiasm or tract). In this case, direct optic nerve compression from perineural haematoma was suggested as a cause for retrobulbar optic neuropathy.

Acute retrobulbar optic neuropathy as the sole manifestation of subarachnoid haemorrhage from a ruptured anterior communicating artery aneurysm.
Lee K, Young Shin S, Hae Park S.
NEURO-OPHTHALMOLOGY
2013;37(4):172-4.