Brain-derived neurotrophic factor in patients with age-related cataract

We measured the contents of brain-derived neurotrophic factor (BDNF) in the lacrimal fluid, aqueous humor, and blood serum in 40 patients (40 eyes) with age-related cataracts. Collection of stimulated lacrimal fluid was performed by a pipette on the day preceding surgery; the aqueous humor and the blood were sampled during the phacoemulsification of a cataract. BDNF was measured using an enzyme immunoassay. On average, the concentration of BDNF in patients was 121.2 ± 47.7 pg/mL in the lacrimal fluid, 52.2 ± 25.7 pg/mL in the aqueous humor, and 23418 ± 7645 pg/mL in the blood serum. The concentration of BDNF in the aqueous humor correlated well with its content in the lacrimal fluid (Pearson’s correlation coefficient was 0.61, P < 0.000) and was below it by a factor of 0.44 ± 0.19 on average. The data we obtained may be used for an approximate evaluation of the BDNF concentration in the aqueous humor on the basis of an analysis of the lacrimal fluid.