The Management of Transient Monocular Visual Loss

Emergent cervical surgical embolectomy to rescue total monocular blindness due to simultaneous cervical internal and external carotid artery occlusion by cardiogenic emboli

Background:

Central retinal artery occlusion (CRAO) is a stroke of the retina and is associated with extremely poor prognosis. Although the pathophysiology of CRAO is diverse, including autoimmune or hematological disorders, neurosurgeons can perform carotid endarterectomy for the causal internal carotid artery stenosis or perform acute recanalization of the extra- or intracranial artery occlusion due to cardiogenic embolism.

Case Description:

A 78-year-old male with a history of atrial fibrillation (Af) visited our hospital with a chief complaint of right monocular blindness. Magnetic resonance imaging revealed occlusion of the right internal and external carotid arteries. We performed emergent cervical surgical embolectomy for restoration of vision. Recanalization was accomplished within 8 h after onset, and the patient regained practical vision within 4 months.

Conclusion:

In the diagnosis and treatment of CRAO, occlusion of the internal and/or external carotid artery due to large cardiac emboli should be taken in consideration, especially when the patient has a history of Af, since acute recanalization might restore vision.

Patterns of non-embolic transient monocular visual field loss

The aim of this study was to systematically describe the semiology of non-embolic transient monocular visual field loss (neTMVL). We conducted a retrospective case note analysis of patients from Moorfields Eye Hospital (1995-2007). The variables analysed were age, age of onset, gender, past medical history or family history of migraine, eye affected, onset, duration and offset, perception (pattern, positive and negative symptoms), associated headache and autonomic symptoms, attack frequency, and treatment response to nifedipine. We identified 77 patients (28 male and 49 female). Mean age of onset was 37 years (range 14-77 years). The neTMVL was limited to the right eye in 36 % to the left in 47 % and occurred independently in either eye in 5 % of cases. A past medical history of migraine was present in 12 % and a family history in 8 %. Headache followed neTMVL in 14 % and was associated with autonomic features in 3 %. The neTMB was perceived as grey in 35 %, white in 21 %, black in 16 % and as phosphenes in 9 %. Most frequently neTMVL was patchy 20 %. Recovery of vision frequently resembled attack onset in reverse. In 3 patients without associated headache the loss of vision was permanent. Treatment with nifedipine was initiated in 13 patients with an attack frequency of more than one per week and reduced the attack frequency in all. In conclusion, this large series of patients with neTMVL permits classification into five types of reversible visual field loss (grey, white, black, phosphenes, patchy). Treatment response to nifidipine suggests some attacks to be caused by vasospasm.