Anterior communicating artery aneurysm presenting as monocular blindness

Area of Science:

• Neuroscience
• Ophthalmology
• Vascular Neurology

Background:

• Anterior communicating artery (AcomA) aneurysms are typically asymptomatic until rupture.
• Monocular visual loss is an uncommon presentation for intracranial aneurysms.
• Retrobulbar optic neuritis is a common cause of sudden monocular vision loss.

Observation:

• A patient presented with rapidly progressing monocular visual loss.
• The visual loss was initially misdiagnosed as retrobulbar optic neuritis.
• Standard steroid therapy for optic neuritis provided no improvement.

Findings:

• A large AcomA aneurysm was identified as the cause of the visual deficit.
• The aneurysm caused direct compression of the optic nerve.
• Rupture of the aneurysm was a critical event in diagnosis.

Implications:

• This case underscores the importance of considering vascular compression in unexplained visual loss.
• Aneurysms, particularly AcomA aneurysms, should be included in the differential diagnosis of acute monocular blindness.
• Prompt diagnosis and management of such aneurysms are crucial to prevent catastrophic rupture and preserve vision.