Brain-derived neurotrophic factor as a biomarker in primary open-angle glaucoma

To introduce a novel biomarker for screening of primary open-angle glaucoma (POAG) by detecting and measuring brain-derived neurotrophic factor (BDNF) in the serum of normal subjects and patients with early stage of glaucoma.

Twenty-five glaucoma patients as the case group and 25 age- and sex-matched normal persons as the control group were tested. The control group comprised 19 men and 6 women, with the mean age of 59.32 ± 11.8 years and without any apparent ocular or systemic diseases. The case group comprised 20 men and 5 women, with the mean age of 59.64 ± 11.56 years, who were assessed by routinely performed clinical and paraclinical investigations. BDNF levels in serum were determined by enzyme-linked immunosorbent assay using monoclonal antibodies specific for BDNF.

The mean of BDNF levels in the serum was 27.16 ± 5.53 ng/mL in the control subjects and 18.42 ± 4.05 ng/mL in the subjects with the early stage glaucoma. A statistically significant difference was evident between the two groups (p < 0.05). We found no significant differences in serum BDNF levels according to the subjects' age, gender, duration of the glaucoma, mean intraocular pressure, and blood pressure (p > 0.05). Glaucoma patients who had lower serum BDNF concentration had disclosed a significant negative correlation with pattern standard deviations.

We conclude that BDNF in the serum might be a useful biochemical marker for early detection of POAG. We also propose that this might be a reliable, time efficient, and cost-effective method for diagnosis, screening, and assessing the progression of POAG. However, more studies and trials are needed to investigate these factors in greater detail.