Proteomic profile analysis of plasma and aqueous humor from glaucoma and non-glaucomatous patients

Abstract

Purpose: Glaucoma, a multifactorial ocular neuropathic and age associated disease, can lead to irreversible vision loss. Diagnosis involves assessing optic cupping (increased cup-to-disc ratios) and structural changes (like retinal nerve fiber layer thinning) through clinical imaging. Elevated intraocular pressure (IOP) is commonly associated with glaucoma, but not always. However, understanding disease progression is hindered by limited access to donor ocular tissue and consistent clinical data. Our study focuses on live patient samples, analyzing their proteome for potential biomarkers to enhance precise diagnosis and monitor glaucoma progression. Methods: Aqueous humor (AH) samples were collected from 36 glaucoma patients (17 male, 19 female), and 35 non-glaucomatous control patients (16 male, 19 female) undergoing cataract surgery. The protein profile was compared using the SOMAscan assay system for proteome profiling. From glaucomatous donors, significant correlations between IOP and cup-to-disc ratios to proteome differences were identified. Results: Correlations in proteins between plasma and AH were identified. These proteins were enriched in pathways related to vascular integrity, inflammatory response, humoral & adaptive immune response, cell-cell & cell-matrix adhesion, and complement activation. Glaucomatous AH exhibited increased protein levels in general. Neurofilament light chain (NEFL) protein correlated with elevated IOP and inflammatory markers, but not with cup-to-disc ratios. Conclusions: Together, our data demonstrate that the proteins identified in this study from glaucomatous donors correspond to both markers of neurodegeneration and those that may inhibit cell proliferation or disrupt vascular integrity.