Laser Speckle Blood Flow of the Choroid is Significantly Reduced in Patients with Acute Arteritic Anterior Ischemic Optic Neuropathy caused by Giant Cell Arteritis (GCA)

Abstract

Purpose : We sought to differentiate patients with acute arteritic anterior ischemic optic neuropathy (AAION) from patients with non-arteritic anterior ischemic optic neuropathy (NAION) using non-invasive quantification of choroidal blood flow using laser speckle flowgraphy (LSFG). Since AAION is due to vascular occlusion of at least one posterior ciliary artery supplying the choroid and optic nerve head, it was anticipated that choroidal blood flow would be decreased.

Methods : Laser speckle flowography (Softcare, Japan) was used to record relative ocular blood flow quantified by the degree of blur of a laser speckle pattern by moving blood cells in the imaging plane. The dynamics of blood flow during the cardiac cycle were measured in the choroid, major retinal arteries and veins and anterior optic nerve head. Systolic, diastolic, and intraocular pressures were measured to derive relative ocular perfusion pressure. Vascular resistance was quantified by dividing ocular perfusion pressure by mean speckle blur rate of the vascular region of interest. Eyes from the following patient groups were compared: 16 patients with (+)biopsy for giant cell arteritis (four eyes from patients with acute AAION and one eye from 12 patients without AAION) , three eyes from three patients with (-)biopsy for giant cell arteritis, and 20 eyes from 20 patients from acute NAION.

Results : Choroidal vascular resistance was significantly higher (and blood flow lower) in acute AAION eyes compared to the other groups (ANOVA rank test, nonparametric analysis; p=0.039). The subgroup analysis showed that choroidal vascular resistance was significantly higher compared to eyes from patients with NAION.

Conclusions : A significant decrease in choroidal blood flow and increase in vascular resistance was found in patients with acute AAION who had a positive temporal artery biopsy using laser speckle blood flowgraphy. Measurement of choroidal vascular resistance may be an alternative approach to fluorescein angiography for diagnosis and monitoring treatment of giant cell arteritis.

This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.