Complex hemodynamics of intervortex vein anastomoses in highly myopic eyes.

Abstract

To analyze the complex pattern of filling of the intervortex vein (IVV) anastomoses through large trunks in highly myopic (HM) eyes based on indocyanine green angiographic (ICGA) videos. The medical records of 1060 consecutive HM eyes that had undergone ICGA were studied. IVV anastomoses were identified in the ICGA images, and the ICGA images and videos were analyzed comprehensively to characterize their hemodynamic features. Seven eyes with IVV anastomoses through large trunks were analyzed. In the ICGA videos of six eyes, laminar flow was observed in the IVV anastomotic vessels that started in the arterial phase in 2 eyes, with pulsatile fashion in 1 of them. The flow began in the early arteriovenous transition phase in 4 eyes. The laminar flow continued for a mean of 12.17±3.06 seconds, and the remaining section was gradually filled slower than the surrounding veins. The anastomotic trunk for the remaining 1 eye was too narrow to be analyzed. Four eyes had longitudinal ICGA records, and 2 had significant attenuation and narrowing of the anastomotic vessels. The very early filling of part of the IVV anastomoses suggests that arterio-venous anastomoses is involved in the IVV of HM eyes. However, this suggestion needs further study. There may be similar pathogenesis for IVV anastomoses either in thick or thin sclera.