title: Corneal confocal microscopy for the diagnosis of diabetic autonomic neuropathy.
abstract: BACKGROUND
  Diabetic autonomic neuropathy (DAN) results in increased morbidity and mortality. The early diagnosis of DAN can be difficult and is commonly evaluated using cardiac autonomic function tests as a surrogate. However, they are not widely available, have limited sensitivity and specificity, and can be confounded by concomitant cardiovascular disease and medications.
  
  
  METHODS
  The diagnostic utility of corneal confocal microscopy for diagnosis of DAN was assessed. Thirty-four diabetic patients without [Composite Autonomic Scoring Scale (CASS)≤2] vs with (CASS>2) DAN and 18 healthy control subjects (HC) underwent detailed assessment of somatic and autonomic neuropathy, Composite Autonomic Symptom Scale (COMPASS), (CASS), and Corneal Confocal Microscopy (CCM).
  
  
  RESULTS
  Corneal nerve fiber density, branch density, and length showed a progressive and significant reduction in patients with DAN vs HC and those without DAN. CCM correlated highly significantly with COMPASS and CASS, and corneal nerve fiber parameters demonstrated a high sensitivity and specificity for diagnosis of DAN.
  
  
  CONCLUSIONS
  This study demonstrates that corneal nerve damage detected using CCM can be deployed to diagnose subclinical and overt DAN. It therefore represents a rapid, non-invasive, highly sensitive and specific diagnostic test for DAN.
authors.affiliation: Centre for Endocrinology & Diabetes, Institute of Human Development, Faculty of Medical and Human Sciences, University of Manchester.
authors.forename: Mitra
authors.initials: M
authors.lastname: Tavakoli
authors.affiliation: Gastrointestinal Centre, Institute of Inflammation and Repair, Faculty of Medical and Human Sciences, University of Manchester.
authors.forename: Piyara
authors.initials: P
authors.lastname: Begum
authors.affiliation: Gastrointestinal Centre, Institute of Inflammation and Repair, Faculty of Medical and Human Sciences, University of Manchester.
authors.forename: John
authors.initials: J
authors.lastname: McLaughlin
authors.affiliation: Centre for Endocrinology & Diabetes, Institute of Human Development, Faculty of Medical and Human Sciences, University of Manchester.|Weill Cornell Medical College in Qatar.
authors.forename: Rayaz A
authors.initials: RA
authors.lastname: Malik
mesh_terms: D000328:Adult; D001342:Autonomic Nervous System Diseases / Q000175:diagnosis* / Q000209:etiology / Q000473:pathology; D016022:Case-Control Studies; D003315:Cornea / Q000294:innervation / Q000473:pathology*; D003922:Diabetes Mellitus, Type 1 / Q000150:complications / Q000473:pathology*; D003924:Diabetes Mellitus, Type 2 / Q000150:complications / Q000473:pathology*; D003929:Diabetic Neuropathies / Q000175:diagnosis* / Q000209:etiology / Q000473:pathology; D042241:Early Diagnosis; D005260:Female; D006801:Humans; D008297:Male; D018613:Microscopy, Confocal; D009412:Nerve Fibers / Q000473:pathology*; D012680:Sensitivity and Specificity
keywords: Autonomic Neuropathy; Corneal confocal microscopy; Corneal nerves; Diabetes