title: Tear production and corneal sensitivity in diabetes.
abstract: OBJECTIVE
  Diabetic patients are at significant risk of developing corneal lesions such as superficial punctate keratitis, recurrent corneal erosions, persistent epithelial defects, and microbial keratitis. The aim of this study was to investigate whether diabetes mellitus is correlated with both reduced corneal sensation and reduced tear production.
  
  
  METHODS
  In 25 type II diabetic patients with a history of retinopathy only and in 25 nondiabetic control subjects (age and sex matched), we performed noncontact corneal aesthesiometry and assessed basal tear production using Schirmer's test with topical anesthesia. The noncontact corneal aesthesiometer (NCCA) is a new noninvasive device for quantifying threshold corneal sensitivity.
  
  
  RESULTS
  The diabetic patients demonstrated a significantly reduced Schirmer's test result (P<.001) and significantly reduced corneal sensitivity (P<.01).
  
  
  CONCLUSIONS
  Our study supports previous reports of reduced basal tear production, lending more support to the theory of a peripheral neuropathy affecting lacrimal gland function in diabetes. We also confirmed reduced threshold corneal sensitivity in diabetic patients using the NCCA.
authors.affiliation: Princess Alexandra Eye Pavilion, Edinburgh, UK.
authors.forename: Pippa
authors.initials: P
authors.lastname: Cousen
authors.forename: Peter
authors.initials: P
authors.lastname: Cackett
authors.forename: Harry
authors.initials: H
authors.lastname: Bennett
authors.forename: Ken
authors.initials: K
authors.lastname: Swa
authors.forename: Bal
authors.initials: B
authors.lastname: Dhillon
mesh_terms: D000368:Aged; D003315:Cornea / Q000503:physiopathology*; D003920:Diabetes Mellitus / Q000503:physiopathology*; D003930:Diabetic Retinopathy / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012016:Reference Values; D012680:Sensitivity and Specificity; D013666:Tears / Q000378:metabolism*; D014787:Vision Tests