"Phosphene": early sign of vascular compression neuropathy of the optic nerve

Dolichoectasia of the ophthalmic artery: a case report on the treatment strategy in endovascular therapy and literature review

BACKGROUND

Dolichoectasia is a rare arterial condition characterized by the dilatation, tortuosity, and elongation of cerebral blood vessels. The vertebrobasilar artery and internal carotid artery are the common sites of dolichoectasia. However, dolichoectasia of the branch arteries, such as the ophthalmic artery (OA), is extremely rare. To the best of our knowledge, this is the first case of ophthalmic dolichoectasia that was successfully treated with endovascular internal coil trapping.

CASE PRESENTATION

A 54-year-old female patient presented with transient left ophthalmalgia and visual disturbance. Magnetic resonance imaging revealed a dilated and elongated left OA compressing the optic nerve at the entrance of the optic canal. However, a previous image that was taken 17 years back revealed that the OA was normal, which suggested the change in dolichoectasia was acquired. Cerebral angiography showed that the dilated and tortuous OA was running from the ophthalmic segment of the left internal carotid artery into the orbit. The symptoms could have been attributed to the direct compression of the dolichoectatic OA in the optic canal. A sufficient anastomosis between the central retinal artery and the middle meningeal artery was identified on external carotid angiography with balloon occlusion of the internal carotid artery. Endovascular treatment with internal trapping of the OA was performed due to ophthalmic symptom progression. Internal coil trapping of the OA was performed at the short segment between the OA bifurcation and the entrance of the optic canal. As expected, the central retinal artery was supplied via the middle meningeal artery after the treatment. The transient visual disturbance was immediately resolved. Ophthalmalgia worsened temporarily after the treatment. However, it completely resolved after several days of oral corticosteroid therapy. Postoperative angiography showed that the origin of the OA was occluded and that the OA in the optic canal was shrunk. The flow of the central retinal arteries via the middle meningeal artery was preserved.

CONCLUSIONS

OA dolichoectasia is rare, and its pathogenesis and long-term visual prognosis are still unknown. However, endovascular therapy can improve symptom by releasing the pressure site in the optic canal.

Vascular Compression of the Anterior Optic Pathway: A Rare Occurrence?

BACKGROUND

Vascular compression of the anterior optic pathway has been documented as an infrequent cause of visual impairments. Here we characterize such vascular compression using magnetic resonance imaging.

METHODS

A total of 183 patients without pathologies affecting the optic pathways underwent T2-weighted or constructive interference steady-state sequence magnetic resonance imaging. Imaging data from coronal sections were analyzed.

RESULTS

A vascular compression of the anterior optic pathway was identified in 20 patients (11%). They comprised 13 men and 7 women with a mean age of 60.8 years. The vascular compressions were observed at 22 sites, 15 on the optic nerve (ON) and 7 on the optic chiasm (OC). Twelve of them were on the right and 10 were on the left side. The offending vessels were the supraclinoid portion of the internal carotid artery in 86.4% and the A1 segment of the anterior cerebral artery in 13.6%. Compression sites at the ON and OC were variable, with the inferolateral surface being the most frequent (77.3% occurrences). In 2 patients (9.1%), the ON was compressed in a sandwich manner.

CONCLUSIONS

Vascular compression of the ON and OC may not be an infrequent occurrence in the cranial cavity. Progressive and unexplainable visual impairment might possibly be caused by vascular-compressive neuropathy.