Purpose: 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.
Methods: We performed both scanning laser Doppler flowmetry and indocyanine green angiography with a scanning laser ophthalmoscope in the same patient.
Results: 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.
Conclusion: The circle of Zinn-Haller can be visualized in vivo because of the peripapillary atrophy.