Computed tomographic angiogram of an anterior communicating artery aneurysm causing acute retrobulbar optic neuropathy: a case report

Complete Recovery from Blindness in Case of Compressive Optic Neuropathy due to Unruptured Anterior Cerebral Artery Aneurysm

It is not common for an isolated visual symptom to be the first indication of an aneurysm compressing the optic nerve. The compression can lead to blindness, and a recovery from the blindness is rare. We report a female with a left painless optic neuropathy caused by an unruptured anterior cerebral artery aneurysm. The patient had a temporal hemianopic visual field defect, which progressed to blindness in the left eye, while the right visual function was not affected. A coil embolization of the aneurysm completely restored her visual acuity to 20/20. These findings suggest that aneurysmal lesions should be ruled out in case of unilateral optic neuropathy with hemianopic visual field defects and progressive visual loss.

Imaging of Optic Neuropathy and Chiasmal Syndromes

Optic neuropathy involves loss of visual acuity, color vision, and visual field defect with a swollen, pale, anomalous, or normal optic disc seen on fundoscopy. Chiasmal disorders classically present with gradual onset of vision loss, bitemporal hemianopsia, and occasionally, endocrinopathy if the pituitary gland and/or hypothalamus are the causes or are involved. Advance in neuroimaging, especially magnetic resonance (MR) imaging, can reveal pathologic conditions previously detected only clinically. Some entities have imaging characteristics, leading to appropriate treatment without requiring tissue biopsies. Imaging also provides disease surveillance and posttreatment assessment, with computed tomography and MR imaging being complementary to each other.

Acute Retrobulbar Optic Neuropathy as the Sole Manifestation of Subarachnoid Haemorrhage from a Ruptured Anterior Communicating Artery Aneurysm

Anterior communicating artery aneurysm is the most common form of intracranial aneurysm and subarachnoid haemorrhage (SAH) is the common presenting feature of anterior communicating artery aneurysms. In general, patients with SAH from anterior communicating artery aneurysm present with neurological deficit. We report an interesting case of a 60-year-old man who presented with acute monocular vision loss accompanied by periorbital pain without any neurological deficit, finally diagnosed with SAH from ruptured anterior communicating artery aneurysm. Five months after immediate craniotomy with aneurysm neck clipping, his visual acuity was improved to 20/63 with a pale optic disc appearance. Acute retrobulbar optic neuropathy may be the sole manifestation of SAH from ruptured anterior communicating artery aneurysm. Unilateral decrease of visual acuity with periorbital pain, in the absence of other neurological change, may be the initial and isolated sign.