Serum Brain-Derived Neurotrophic Factor in Glaucoma Patients in Japan: An Observational Study

Purpose: The aim of this study was to measure serum levels of brain-derived neurotrophic factor (BDNF) in Japanese patients with primary open angle glaucoma (POAG) and normal tension glaucoma (NTG). Methods: This was a prospective observational study of serum BDNF levels in 78 patients who underwent cataract surgery or trabeculectomy (27 glaucoma patients and 51 non-glaucoma cataract patients as controls). Patient age was 68.8 +/- 11.1 years (mean +/- standard deviation; range 35-86 years). The numbers of patients with POAG and NTG were 16 and 11, respectively. POAG was diagnosed by intraocular pressure measurement, gonioscopy, optic nerve head change, and presence of a visual field defect. Results: Serum BDNF concentration was significantly lower in the glaucoma group (including both POAG and NTG) than in the control group (7.2 +/- 3.6 ng/mL vs. 12.2 +/- 9.3 ng/mL, p=0.004). Serum BDNF concentration was lower in early glaucoma than in moderate glaucoma. There was no correlation between serum BDNF concentration and age. When patients with NTG and POAG were compared, serum BDNF concentration was lower in the former. Serum BDNF concentration was not significantly correlated with glaucoma parameters, including optical coherence tomography and visual field defects. Conclusion: This is the first study to investigate serum BDNF concentration in glaucoma patients in Japan. Future studies should evaluate the role of BDNF as a potential biomarker of glaucoma.