From: Grading fluorescein angiograms in malarial retinopathy
Vessel type | Description |
---|---|
Capillary | Smallest vessel visible on a well focussed angiogram image |
Post-capillary venule | Formed by the confluence of two or more capillaries, and extends up to the point where it is joined by a second post-capillary venule or other larger venular segment |
Pre-capillary arteriole | Extends upstream from the divergence of two or more capillaries to the point where it branches from another pre-capillary arteriole or other larger arteriolar segment |
Post-capillary venule complex | Extends approximately 1/3 of a disc diameter (~500 μm) downstream from the capillaries along venular segments |
Pre-capillary arteriole complex | Extends approximately 1/3 of a disc diameter (~500 μm) upstream from the capillaries along arteriolar segments |
Small venule | Extends from the edge of the post-capillary venule complex downstream to the point of confluence with another venule of similar or larger caliber |
Small arteriole | Extends from the edge of the pre-capillary arteriole complex upstream to the point of branching with another arteriole of similar or larger caliber |
Large venule | Extends downstream from the point of confluence that defines the upper caliber boundary of small vessel segments to the edge of the optic disc |
Large arteriole | Extends upstream from the branching point that defines the upper caliber boundary of small arteriolar segments to the edge of the optic disc |