title: Retinal nerve fibre layer thinning associated with diabetic peripheral neuropathy.
abstract: OBJECTIVE
  To investigate the relationship between retinal nerve fibre layer thickness and peripheral neuropathy in patients with Type 2 diabetes, particularly in those who are at higher risk of foot ulceration.
  
  
  METHODS
  Global and sectoral retinal nerve fibre layer thicknesses were measured at 3.45 mm diameter around the optic nerve head using optical coherence tomography (OCT). The level of neuropathy was assessed in 106 participants (82 with Type 2 diabetes and 24 healthy controls) using the 0-10 neuropathy disability score. Participants were stratified into four neuropathy groups: none (0-2), mild (3-5), moderate (6-8), and severe (9-10). A neuropathy disability score ≥ 6 was used to define those at higher risk of foot ulceration. Multivariable regression analysis was performed to assess the effect of neuropathy disability scores, age, disease duration and retinopathy on RNFL thickness.
  
  
  RESULTS
  Inferior (but not global or other sectoral) retinal nerve fibre layer thinning was associated with higher neuropathy disability scores (P = 0.03). The retinal nerve fibre layer was significantly thinner for the group with neuropathy disability scores ≥ 6 in the inferior quadrant (P < 0.005). Age, duration of disease and retinopathy levels did not significantly influence retinal nerve fibre layer thickness. Control participants did not show any significant differences in thickness measurements from the group with diabetes and no neuropathy (P > 0.24 for global and all sectors).
  
  
  CONCLUSIONS
  Inferior quadrant retinal nerve fibre layer thinning is associated with peripheral neuropathy in patients with Type 2 diabetes, and is more pronounced in those at higher risk of foot ulceration.
authors.affiliation: Institute of Health and Biomedical Innovation, Queensland University of Technology, Kelvin Grove, Queensland, Australia.
authors.forename: A M
authors.initials: AM
authors.lastname: Shahidi
authors.forename: G P
authors.initials: GP
authors.lastname: Sampson
authors.forename: N
authors.initials: N
authors.lastname: Pritchard
authors.forename: K
authors.initials: K
authors.lastname: Edwards
authors.forename: D
authors.initials: D
authors.lastname: Vagenas
authors.forename: A W
authors.initials: AW
authors.lastname: Russell
authors.forename: R A
authors.initials: RA
authors.lastname: Malik
authors.forename: N
authors.initials: N
authors.lastname: Efron
mesh_terms: D000368:Aged; D003924:Diabetes Mellitus, Type 2 / Q000175:diagnosis / Q000503:physiopathology*; D017719:Diabetic Foot / Q000175:diagnosis / Q000503:physiopathology*; D003929:Diabetic Neuropathies / Q000175:diagnosis / Q000503:physiopathology*; D004185:Disability Evaluation; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009412:Nerve Fibers / Q000473:pathology*; D009898:Optic Disk / Q000473:pathology*; D012160:Retina / Q000473:pathology*; D018570:Risk Assessment; D012307:Risk Factors; D012720:Severity of Illness Index; D041623:Tomography, Optical Coherence