Fundus and fluorescein angiographic images of OIR mice.

<p>Control (CTL) mice housed under normal room air oxygen saturation showed fully grown retinal vessels with no avascular areas, tortuous vessels, vessel tufts, or fluorescein leakage at both P17 and P21. Retinas of mice in both saline-treated OIR (OIR) and metformin-treated OIR (+Met) groups exhibited central avascular areas, tortuous vessels, vessel tufts, and fluorescein leakage. At P17, the retinopathy features were similar between the two OIR groups, but at P21, metformin-treated OIR showed poorer vessel growth and diminished retinopathy regression.