Abstract: Retinal ganglion cells (RGCs) receive synaptic inputs through their dendritic trees in the inner plexiform layer (IPL) and convey the visual information via their axons which form the optic nerve to the brain (Sanes and Masland, 2015). In glaucoma, RGCs and their axons degenerate and die, leading to irreversible vision loss and eventually blindness if left untreated (Quigley, 2016). The self-destructive programs in RGCs induced by glaucomatous insults are often spatially compartmentalized (Syc-Mazurek and Libby, 2019), which results in changes in the IPL, the ganglion cell layer, and the retinal nerve fiber layer (RNFL) before cell death in humans and rodents (Wollstein et al., 2012; Chen et al., 2015; Grannonico et al., 2021). Characterizing RGC morphological changes is thus potentially pertinent for timely intervention to preserve RGCs and vision, but much remains unknown to establish a sensitive and specific marker of RGC damage for better diagnosis and management of glaucoma.