The Associations of Plasma Brain-derived Neurotrophic Factor with Macular Structure and Visual Function in Open-angle Glaucoma: A Cross-sectional Study

Précis: Plasma BDNF differed across glaucoma severity stages and was cross-sectionally associated with visual and structural parameters; in exploratory age-stratified analyses, the fitted csGCCT–BCVA relationship differed between younger and older patients. Purpose: To compare the plasma level of brain-derived neurotrophic factor (BDNF) in open-angle glaucoma (OAG) patients across disease stages and to examine its associations with visual and structural parameters. Patients and Methods: This cross-sectional study included 167 control (cataract) patients and 800 patients with OAG. Plasma BDNF level was measured using a bead-based immunoassay (Luminex). Clinical variables included best-corrected visual acuity (BCVA), Humphrey Field Analyzer 24-2 indices, and swept-source optical coherence tomography measurements of superior, central, and inferior papillomacular central-strip ganglion cell complex thickness (csGCCT). Glaucoma severity was classified with the Anderson-Patella criteria. Exploratory generalized additive models characterized the central csGCCT–BCVA relationship by age group and by lowest versus highest quartile. Results: Plasma BDNF was lower in early and moderate glaucoma patients than in controls ( P =0.006, 0.001) but higher in advanced than in early or moderate glaucoma patients ( P =0.040, 0.006). The highest-BDNF-quartile glaucoma patients had worse BCVA and mean deviation (MD) than the lowest-quartile patients, with significantly lower central csGCCT. Among patients aged <60 years, the fitted central csGCCT–BCVA relationship differed between the highest and lowest BDNF quartiles, with higher fitted logMAR in the highest-quartile group at lower csGCCT values. Conclusions: Plasma BDNF level differed across OAG disease stages and was associated with visual and structural parameters. Among younger patients, plasma BDNF quartile was associated with the fitted csGCCT–BCVA relationship. These cross-sectional findings do not establish temporal or causal relationships.