title: Exploring Serum Levels of Brain Derived Neurotrophic Factor and Nerve Growth Factor Across Glaucoma Stages.
abstract: OBJECTIVE
  To investigate the serum levels of Brain Derived Neurotrophic Factor (BDNF) and Nerve Growth Factor (NGF) in patients affected by primary open angle glaucoma with a wide spectrum of disease severity compared to healthy controls and to explore their relationship with morphological and functional glaucoma parameters.
  
  
  METHODS
  45 patients affected by glaucoma at different stages and 15 age-matched healthy control subjects underwent visual field testing, peripapillary retinal nerve fibre layer thickness measurement using Spectral Domain Optical Coherence Tomography and blood collection for both neurotrophins detection by Enzyme-Linked Immunosorbent Assay. Statistical analysis and association between biostrumental and biochemical data were investigated.
  
  
  RESULTS
  Serum levels of BDNF in glaucoma patients were significantly lower than those measured in healthy controls (261.2±75.0 pg/ml vs 313.6±79.6 pg/ml, p = 0.03). Subgroups analysis showed that serum levels of BDNF were significantly lower in early (253.8±40.7 pg/ml, p = 0.019) and moderate glaucoma (231.3±54.3 pg/ml, p = 0.04) but not in advanced glaucoma (296.2±103.1 pg/ml, p = 0.06) compared to healthy controls. Serum levels of NGF in glaucoma patients were significantly lower than those measured in the healthy controls (4.1±1 pg/mL vs 5.5±1.2 pg/mL, p = 0.01). Subgroups analysis showed that serum levels of NGF were significantly lower in early (3.5±0.9 pg/mL, p = 0.0008) and moderate glaucoma (3.8±0.7 pg/ml, p<0.0001) but not in advanced glaucoma (5.0±0.7 pg/ml, p = 0.32) compared to healthy controls. BDNF serum levels were not related to age, visual field mean deviation or retinal nerve fibre layer thickness either in glaucoma or in controls while NGF levels were significantly related to visual field mean deviation in the glaucoma group (r2 = 0.26, p = 0.004).
  
  
  CONCLUSIONS
  BDNF and NGF serum levels are reduced in the early and moderate glaucoma stages, suggesting the possibility that both factors could be further investigated as potential circulating biomarkers for the early detection of glaucoma.
authors.affiliation: IRCCS-Fondazione GB Bietti, Rome, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Oddone
authors.affiliation: IRCCS-Fondazione GB Bietti, Rome, Italy.
authors.forename: Gloria
authors.initials: G
authors.lastname: Roberti
authors.affiliation: IRCCS-Fondazione GB Bietti, Rome, Italy.
authors.forename: Alessandra
authors.initials: A
authors.lastname: Micera
authors.affiliation: IRCCS-Fondazione GB Bietti, Rome, Italy.
authors.forename: Anna
authors.initials: A
authors.lastname: Busanello
authors.affiliation: Department of Ophthalmology, Campus Bio-Medico University, Rome, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Bonini
authors.affiliation: Section of Ophthalmology, Department of Medical and Surgical Specialties, Radiological Sciences, and Public Health University of Brescia, Brescia, Italy.
authors.forename: Luciano
authors.initials: L
authors.lastname: Quaranta
authors.affiliation: Ophthalmology Clinic, Department of Medicine and Aging Science, "G. d'Annunzio" University of Chieti-Pescara, Chieti, Italy.
authors.forename: Luca
authors.initials: L
authors.lastname: Agnifili
authors.affiliation: DSCMT, University of Rome Tor Vergata, Rome, Italy.
authors.forename: Gianluca
authors.initials: G
authors.lastname: Manni
mesh_terms: D000367:Age Factors; D000368:Aged; D019208:Brain-Derived Neurotrophic Factor / Q000097:blood*; D016022:Case-Control Studies; D003941:Diagnostic Techniques, Ophthalmological; D005260:Female; D005901:Glaucoma / Q000097:blood* / Q000175:diagnosis* / Q000188:drug therapy; D006801:Humans; D008297:Male; D008875:Middle Aged; D020932:Nerve Growth Factor / Q000097:blood*; D012165:Retinal Ganglion Cells / Q000378:metabolism / Q000473:pathology; D012720:Severity of Illness Index; D012737:Sex Factors
chemical_list: D019208:Brain-Derived Neurotrophic Factor; D020932:Nerve Growth Factor