Retinal vascular permeability in living animals was assessed as described before (34 (link)). Briefly, rats were anesthetized (ketamine, 100 mg/kg; xylazine, 30 mg/kg; and acepromazine, 10 mg/kg). Pupils were dilated using 1% tropicamide (Bausch & Lomb, Rochester, NY), and Goniovisc 2.5% (hypromellose; Sigma Pharmaceuticals, LLC, Monticello, IA) was applied liberally to retain surface moisture during imaging. Each animal was placed on the imaging platform of the Phoenix Micron III retinal imaging microscope (Phoenix Research Laboratories, Pleasanton, CA), and an intraperitoneal injection (80–100 μL) of fluorescein sodium (10% Lite) (Apollo Ophthalmics, Newport Beach, CA) was administered. Rapid acquisition of fluorescent images ensued for ∼5 min. For a quantitative evaluation of blood-retinal barrier (BRB) integrity, we assessed albumin extravasation in rats after perfusion (34 (link),35 (link)). Serum albumin levels were measured in the perfused retinal tissue by Western blot using anti-rat albumin antibody (Cell Signaling Technology, Danvers, MA).