Usefulness of Laser Speckle Flowgraphy for the Assessment of Ocular Blood Flow in Extracranial-Intracranial Bypass

Laser speckle flowgraphy (LSFG) is a noninvasive technique that can measure relative blood flow velocity in the optic fundus. The authors present a case of symptomatic internal carotid artery occlusion treated with superficial temporal artery (STA)-middle cerebral artery (MCA) bypass in which an improvement of ocular circulation was confirmed by LSFG. A 47-year-old man presented with a 1-month history of repeated left blurred vision and motor weakness of the right leg. Diffusion-weighted magnetic resonance imaging revealed a small infarction in the left frontal lobe. Carotid angiography revealed that the left internal carotid artery was occluded at the C4 portion. Single-photon emission computed tomography indicated that the cerebral blood flow in the left MCA territory was markedly impaired. Ophthalmologic examination revealed ischemic change of the left optic fundi, and LSFG revealed decreased blood flow around the left optic disc. Left STA-MCA bypass was successfully performed. Both ischemic ocular symptoms and the ischemic symptoms of the right leg were completely recovered after surgery. Postoperative ophthalmologic examination revealed improvement of both ischemic changes of the left optic fundi. Moreover, LSFG revealed improvement of the blood flow around the left optic disc. LSFG can be a promising clinical tool for the assessment of ocular circulation before and after bypass surgery for occlusive cerebrovascular disease.