Abstract
PURPOSE: The purpose of this study was to determine optic nerve head (ONH) laminar collagen and retrolaminar myelin expression change in non-human-primate (NHP) experimental glaucoma (EG) using immunohistochemistry (IHC) and spatial transcriptomics. METHODS: Unilateral EG NHPs (n = 3) were perfusion fixed, ONHs were trephined, embedded in paraffin, and serial sectioned for IHC and spatial transcriptomics. EG versus control eye retinal nerve fiber layer thickness (RNFLT) and axon loss within each region of study were estimated. RESULTS: CNPase levels decrease in the retrolaminar region of the ONH in early EG by IHC. Multiple myelin genes are decreased in early NHP EG in the retrolaminar region. Inflammatory pathways were upregulated in the retrolaminar region as well. Among the top genes that were altered in the laminar region were collagen-related genes and transforming growth factor beta 1 (TGFβ1). CONCLUSIONS: Spatial transcriptomics analysis revealed a consistent downregulation of multiple myelin-related genes, and IHC confirmed a corresponding decrease in CNPase protein expression. Importantly, spatial transcriptomics identified differential profiles among the prelaminar, laminar, and retrolaminar ONH. Together, these findings highlight early myelin disruption and provide insights into the spatial and molecular dynamics of disease onset in NHP. This work advances our understanding of glaucoma pathogenesis and lays the groundwork for developing novel therapeutic strategies.