title: Corneal nerve loss detected with corneal confocal microscopy is symmetrical and related to the severity of diabetic polyneuropathy.
abstract: OBJECTIVE
  To establish if corneal nerve loss, detected using in vivo corneal confocal microscopy (IVCCM), is symmetrical between right and left eyes and relates to the severity of diabetic neuropathy.
  
  
  METHODS
  Patients (n = 111) with type 1 and type 2 diabetes and 47 age-matched healthy control subjects underwent detailed assessment and stratification into no (n = 50), mild (n = 26), moderate (n = 17), and severe (n = 18) neuropathy. IVCCM was performed in both eyes and corneal nerve fiber density (CNFD), branch density (CNBD), and fiber length (CNFL) and the tortuosity coefficient were quantified.
  
  
  RESULTS
  All corneal nerve parameters differed significantly between diabetic patients and control subjects and progressively worsened with increasing severity of neuropathy. The reduction in CNFD, CNBD, and CNFL was symmetrical in all groups except in patients with severe neuropathy.
  
  
  CONCLUSIONS
  IVCCM noninvasively detects corneal nerve loss, which relates to the severity of neuropathy, and is symmetrical, except in those with severe diabetic neuropathy.
authors.affiliation: Corresponding author: Rayaz A. Malik, rayaz.a.malik@manchester.ac.uk.
authors.forename: Ioannis N
authors.initials: IN
authors.lastname: Petropoulos
authors.forename: Uazman
authors.initials: U
authors.lastname: Alam
authors.forename: Hassan
authors.initials: H
authors.lastname: Fadavi
authors.forename: Omar
authors.initials: O
authors.lastname: Asghar
authors.forename: Patrick
authors.initials: P
authors.lastname: Green
authors.forename: Georgios
authors.initials: G
authors.lastname: Ponirakis
authors.forename: Andrew
authors.initials: A
authors.lastname: Marshall
authors.forename: Andrew J M
authors.initials: AJ
authors.lastname: Boulton
authors.forename: Mitra
authors.initials: M
authors.lastname: Tavakoli
authors.forename: Rayaz A
authors.initials: RA
authors.lastname: Malik
mesh_terms: D000328:Adult; D000368:Aged; D003315:Cornea / Q000294:innervation*; D003922:Diabetes Mellitus, Type 1 / Q000150:complications*; D003924:Diabetes Mellitus, Type 2 / Q000150:complications*; D003929:Diabetic Neuropathies / Q000209:etiology / Q000473:pathology*; D005260:Female; D006801:Humans; D008297:Male; D018613:Microscopy, Confocal; D008875:Middle Aged; D009412:Nerve Fibers / Q000473:pathology*