Monitoring Dynamic Growth of Retinal Vessels in Oxygen-Induced Retinopathy Mouse Model

Oxygen-induced retinopathy (OIR) is widely used to study abnormal vessel growth in ischemic retinal diseases, including retinopathy of prematurity (ROP), proliferative diabetic retinopathy (PDR), and retinal vein occlusion (RVO). Most OIR studies observe retinal neovascularization at specific time points; however, the dynamic vessel growth in live mice along a time course, which is essential for understanding the OIRrelated vessel diseases, has been understudied. Here, we describe a step-by-step protocol for the induction of the OIR mouse model, highlighting the potential pitfalls, and providing an improved method to quickly quantify areas of vaso-obliteration (VO) and neovascularization (NV) using immunofluorescence staining. More importantly, we monitored vessel regrowth in live mice from P15 to P25 by performing fluorescein fundus angiography (FFA) in the OIR mouse model. The application of FFA to the OIR mouse model allows us to observe the remodeling process during vessel regrowth.