Related Experiment Video
Updated: Jan 23, 2026

Optimization of the Retinal Vein Occlusion Mouse Model to Limit Variability
Published on: August 6, 2021
Collateral Vessels in Branch Retinal Vein Occlusion: Anatomic and Functional Analyses by OCT Angiography
Kotaro Tsuboi1, Hirofumi Sasajima1, Motohiro Kamei1
1Department of Ophthalmology, Aichi Medical University, Nagakute, Japan.
Purpose:
To analyze collateral vessels (CVs) associated with branch retinal vein occlusion (BRVO) anatomically and functionally using OCT angiography (OCTA).
Design:
Retrospective review.
Participants:
Twenty-nine consecutive patients with BRVO.
Methods:
The distribution of the CVs 12 months after the onset of BRVO was studied using spectral-domain OCTA. En face 3 × 3-mm OCTA images were acquired from 9 locations centered on the fovea and used to create a montage image of an 8.1 × 8.1-mm square. The CVs were identified in 3 separate areas: the radial peripapillary capillary (RPC), superficial capillary plexus (SCP), and deep capillary plexus (DCP) layers. The numbers of CVs were evaluated in 4 regions: zone 1, the area within a 3-mm diameter circle centered on the fovea; zone 2, the area between the 3-mm diameter circle and its outer 6-mm diameter circle; zone 3, the area beyond the 6-mm diameter circle; and the temporal raphe.
Main Outcome Measures:
The relationship between the number of CVs and vessel density (VD) in each layer, persistent macular edema (ME) at 12 months, and the number of injections of anti-vascular endothelial growth factor (VEGF) agents.
Results:
The number of CVs in zone 1 was correlated negatively (P = 0.0079) with the VD in the SCP, and the numbers of CVs in zone 3 and the temporal raphe were correlated negatively (P = 0.0017 and P = 0.036, respectively) with the VD in the DCP. The number of CVs in the RPC and total number of CVs were also correlated negatively (P = 0.0034 and P = 0.0113, respectively) with the VD in the DCP. In patients with persistent ME, the number of CVs in zone 1 was significantly (P = 0.0156) greater than in patients with nonpersistent ME and correlated positively (P = 0.025) with the number of anti-VEGF injections.
Conclusions:
The CVs in BRVO form as result of capillary dropout and are considered to represent remodeling of the retinal capillaries. The CVs around the fovea may be good indicators of persistent ME.
Related Concept Videos
Sympathetic Pathways: Collateral Ganglia and Adrenal Medulla
Collateral Ganglia
Sympathetic preganglionic axons reach the collateral ganglia along the route of splanchnic nerves. These nerves bypass the sympathetic trunk and communicate with sympathetic postganglionic neurons housed in the prevertebral ganglia. These ganglia supply the organs of the abdominopelvic cavity.
The greater splanchnic nerve, formed by the...
Anatomical Positions
The body is upright, facing forward, and standing erect.
The feet are parallel and flat on the floor.
The arms are hanging by the...
Anatomical Terminology
Anatomical Movements
Here are some common anatomical movements:
Flexion and extension motions are in the sagittal (anterior–posterior) plane of motion. These movements take place at the shoulder, hip, elbow, knee, wrist,...
Veins
Structure of Veins:
The structure of veins is specifically designed to assist in the low-pressure transportation of...
Cerebrum: Anatomical Overview II

