2. Angiographic classification of PSR.

Types	Angiographic appearances of peripheral retinal capillary beds
Type 1	Qualitatively similar to normal, may be displace posteriorly with loss of capillary beds.
Type 2 ‐ Type 2A ‐ Type 2B	Qualitatively abnormal, with abrupt termination of small or medium‐sized vessels. ‐ presence of unstable border with capillary buds or stumps extending into non perfused retina. ‐ absence of capillary buds or stumps.
Type 3	Indeterminate because recent acute arteriolar occlusion involving the vascular border gave rise to a type II pattern that reverted to normal following subsequent reperfusion of the vascular bed.

PSR ‐ Proliferative sickle retinopathy