The Vanderbilt University Medical Center Institutional Animal Use and Care Committee approved all experimental procedures. Young adult (2 mo) C57 mice (C57BL/6, male; Charles River Laboratory) were maintained in a 12-h light/dark cycle with standard rodent chow and water available ad libitum. We used unilateral microbead occlusion to elevate IOP in C57 mice, with the fellow eye receiving an equal volume saline injection as internal control (16 (link)–18 (link, link)). We measured IOP biweekly using rebound tonometry (Tono-Pen XL; Medtronic Solan), as described (16 (link)–18 (link, link)) (Fig. S9). For physiological recordings and intracellular filling, retinas were dissected under long-wavelength light (630 nm, 800 µW/cm2; Ushio FND/FG). A subset of animals was bilaterally injected intravitreally with 1 μL of 0.5 mg cholera toxin subunit B (CTB) conjugated to Alexa Fluor 488 (Invitrogen). Intact transport within serial coronal superior colliculus sections was quantified (18 (link), 23 (link)). For tissue required for immunolabeling of vertical sections and analysis of anterograde transport, mice were perfused transcardially with 4% paraformaldehyde.