Retinal ganglion cell (RGC) density is significantly affected by NF‐L 10H9. (a) RGC density and (b) retinal nerve fibre layer (RNFL) thickness at 15 days (group A, grey bars, n = 3 mice per group, n = 2 for isotype control) or at 20 days (group B, black bars, n = 2 mice per group) after treatment with (un)labelled NF‐L 10H9 or isotype control IgG1. (a) Only mice in group B treated with unlabelled NF‐L 10H9 showed a statistically significant reduction in RGC density compared with mice treated with unlabelled isotype control IgG1 (Student's t‐test, P < 0·05). (b) No significant differences in percentage change in RNFL thickness were observed in NF‐L 10H9‐treated mice 15 or 20 days post‐induction. *P <0·05