In vivo detection of perineural circular arterial anastomosis (circle of Zinn-Haller) in a patient with large peripapillary chorioretinal atrophy.

Abstract

In vivo visualization of perineural circular arterial anastomosis (circle of Zinn-Haller) has been considered impossible because of the arterial circle's location in the sclera. We investigated whether the circle of Zinn-Haller could be detected in a glaucoma patient who had a large area of temporal peripapillary chorioretinal atrophy. We performed both scanning laser Doppler flowmetry and indocyanine green angiography with a scanning laser ophthalmoscope in the same patient. In the area of peripapillary atrophy, a circumferential vascular loop consistent with a portion of the circle of Zinn-Haller could be detected by the two imaging methods. The circle of Zinn-Haller can be visualized in vivo because of the peripapillary atrophy.