Fig 2: Quantification of the retinal nerve fiber layer thickness (RNFLT). To quantify the damage to the retina caused by the chronically elevated IOP in vivo, the retina was examined by optical coherence tomography (OCT). This allows retinal cross-sections to be imaged. The retinal nerve fiber layer was defined and quantified using a semi-automatic segmentation algorithm. For quantification, a 12° diameter circular B-scan was acquired. The Heidelberg Eye Explorer software divides the retina into the main sectors, superior (S), temporal (T), inferior (I), and nasal (N), as well as into the intermediate sectors, temporal superior (TS), temporal inferior (TI), nasal inferior (NI), and nasal superior (NS) (A). The scheme shows the interventions performed during the study on the eye, episcleral vein occlusion (EVO), and intravitreal injection (IVI) (scheme modified from [29]). The mean RNFLT of the whole B-scan was used for follow-up quantification (B). Further quantification of the RNFLT at week 10 was performed for the individual sectors (C–H). Legend: black (IgG OS), blue (HMGB1 OS), light grey (IgG OD), dark grey (HMGB1 OD). * p < 0.05, ** p < 0.01, *** p < 0.001, not significant (ns), one-way ANOVA, Tukey’s HSD post hoc test.

Fig 3: Expression pattern of selected retinal proteins analyzed by an antibody microarray. For the analysis, 10 µg of protein lysate was used. This was labeled, and a size exclusion chromatography column removed excess unbound dye and buffers unfavorable for the array incubation. The altered proteins with respective expressions in the elevated-IOP eyes were shown. ** p < 0.01, * p < 0.05, other p values as indicated, Student’s t-test (A). The protein expression of the high-mobility group box protein 1 (HMGB1) was examined in the IgG animals (OS, OD) and the antibody-treated HMGB1 animals (OS, OD) (B–G).

Fig 4: Ganzfeld electroretinogram (ERG) pattern and quantification of B-wave and PhNR amplitude at week 0 and week 10. ERG recordings were acquired at different time points. The mean values of the ERG recordings of the individual animals were plotted for the time points week 0 (before EVO) and week 10 after EVO (A–D). The flash intensity 1.37 log10 cd·s·m-2 was used for the ERG recordings shown. The B-wave amplitude (*) and the amplitude of the photopic negative response (PhNR, **) were used for quantification. Quantification was performed separately for the B-wave amplitude of the IgG (E) and the HMGB1 group (F) as well as for the PhNR amplitude of the IgG (G) and the HMGB1 group (H). The millivolt decrease was calculated as a percentage difference (? = % change).