## 2 Results
### Attenuated Retinal Ganglion Cell (RGC) Loss by Anti-DNM1L Ab Injection  
To examine the retinal damage caused by IOP elevation more closely, RGCs were stained and quantified by immunostaining with the established marker brain-specific homeobox/POU domain protein 3A (Brn3a, Figure 11). The average RGC density of the whole flatmount was 1169 \(\pm\) 78 RGC/mm\({}^{2}\) in the IgG OS group (Figure 2A). In the DNM1L group, RGC density was significantly higher, with 1723 \(\pm\) 110 RGC/mm\({}^{2}\), compared to the IgG OS group (\(p\) < 0.01). The RGC densities were 1519 \(\pm\) 250 RGC/mm\({}^{2}\) (IgG OD) and 1682 \(\pm\) 370 RGC/mm\({}^{2}\) (DNM1L OD). The RGC density of the IgG OD group was significantly higher compared with the IgG OS group (\(p\) < 0.05), and the comparison of the DNM1L OS and OD showed no significant difference (ns). In this study, the RGC density of the whole flatmount and the regional areas central, mid-peripheral and peripheral were quantified (Figure 2B). The DNM1L OS group had a significantly higher RGC density in the central area with 2180 \(\pm\) 199 RGC/mm\({}^{2}\) compared to 1448 \(\pm\) 112 RGC/mm\({}^{2}\) in the IgG group (_p_ < 0.001). The IgG OD group had an RGC density of 1789 \(\pm\) 253 RGC/mm\({}^{2}\), and the DNM1L group had 2074 \(\pm\) 406 RGC/mm\({}^{2}\), which was not significantly altered compared with the RGC densities in the corresponding OS groups. Figure 1: Longitudinal IOP monitoring. Rebound tonometry was used to examine IOP once a week. IOP was stably elevated three weeks after episcleral vein occlusion (EVO) at the OS. Stable IOPelevation was followed by intravitreal injection (IVI) of either IgG control antibody (IgG OS, Black) or anti-DNM1L antibody (DNM1L OS, Red). The contralateral OD, IgG OD (light gray), and DNM1L OD (dark gray), received no interventions and served as internal controls. IOP remained stably elevated until the end of the study. The increase in w10 was statistically significant. ***\(p\) < 0.0001, student’s _t_-test. Numbers of animals used: \(n\) = 7 (IgG), \(n\) = 8 (DNM1L). Figure 2: Quantitative analysis of Brn3+ RGCs in retinal flatmounts. Retinal ganglion cells were stained using immunostaining of Brn3a. An anti-Brn3a antibody (C20, Santa Cruz, Dallas, TX, USA) was used as the primary antibody and an anti-goat AF568 antibody (Life Technologies, Carlsbad, CA, USA) as the secondary antibody. Single images were taken with a fluorescence microscope (Eclipse TS 100 microscope, Nikon, Yurakucho, Tokyo, Japan), DS-Fi1-U2 digital microscope camera (Nikon, Tokyo, Japan). Objective: ELWD 20\(\times\)/0.45 S Plan Flour Ph1 ADM Air objective (Nikon, Tokyo, Japan). (**A**) Nine images were taken from each flatmount. The RGC number was determined for each image. The average RGC number of the whole flatmount was calculated over all nine images. (**B**) Three of the total nine images were taken for each of the areas central, mid-peripheral, peripheral. For each area, the average RGC density was calculated over the three recordings of one area. *\(p\) < 0.05, **\(p\) < 0.01, ***\(p\) < 0.001, ns = not significant, One-way ANOVA, [PERSON]’s HSD test (post hoc). Numbers of animals used: \(n\) = 7 (IgG), \(n\) = 8 DNM1L. Like in the central region, the DNM1L OS group had significantly higher RGC density in the mid-peripheral with 1812 \(\pm\) 170 RGC/mm\({}^{2}\) compared with 1238 \(\pm\) 169 RGC/mm\({}^{2}\) in the IgG OS group (\(p\) < 0.01). The DNM1L OD group had an RGC density of 1639 \(\pm\) 415 RGC/mm\({}^{2}\), and the IgG OS group had 1564 \(\pm\) 270 RGC/mm\({}^{2}\), which were not significantly changed compared with the corresponding OS groups. In the peripheral area, the DNM1L OS group had an RGC density of 1176 \(\pm\) 240 RGC/mm\({}^{2}\), and the DNM1L OD group had an RGC density of 1333 \(\pm\) 406 RGC/mm\({}^{2}\). The IgG OS group had an average RGC density of 822 \(\pm\) 334 RGC/mm\({}^{2}\), and the IgG OD group had an RGC density of 1202 \(\pm\) 317 RGC/mm\({}^{2}\).