title: Dry eye diagnosis.
abstract: OBJECTIVE
  To determine the most effective objective tests, applied singly or in combination in the diagnosis of dry eye disease.
  
  
  METHODS
  Two groups of subjects--41 with dry eye and 32 with no ocular surface disease--had symptoms, tear film quality, evaporation, tear turnover rate (TTR), volume and osmolarity, and meibomian gland dropout score assessed.
  
  
  RESULTS
  The subjects with dry eye had TTR, tear evaporation, and osmolarity significantly different from that of healthy normal subjects. Cutoff values between the groups were determined from distribution curves for each aspect of tear physiology, and the effectiveness of the cutoff was determined from receiver operator characteristic (ROC) curves. Values of 12%/min for TTR, 33 g/m(-2)/h for evaporation, and 317 mOsmol/L for osmolarity were found to give sensitivities, specificities, and overall accuracies of 80%, 72%, and 77%; 51%, 96%, and 67%; and 78, 78%, and 79%, respectively when applied singly as diagnostic criteria in dry eye. In combination, they yielded sensitivities, specificities, and overall accuracy of 100%, 66%, and 86% (in parallel) and 38%, 100%, and 63% (in series), respectively. Discriminant function analysis incorporating these three factors in an equation allowed diagnosis with a sensitivity of 93%, specificity of 88%, and overall accuracy of 89%.
  
  
  CONCLUSIONS
  Tear osmolarity is the best single test for the diagnosis of dry eye, whereas a battery of tests employing a weighted comparison of TTR, evaporation, and osmolarity measurements derived from discriminant function analysis is the most effective.
authors.affiliation: Department of Vision Sciences, Glasgow Caledonian University, Glasgow, United Kingdom.
authors.forename: Santosh
authors.initials: S
authors.lastname: Khanal
authors.forename: Alan
authors.initials: A
authors.lastname: Tomlinson
authors.forename: Angus
authors.initials: A
authors.lastname: McFadyen
authors.forename: Charles
authors.initials: C
authors.lastname: Diaper
authors.forename: Kannu
authors.initials: K
authors.lastname: Ramaesh
mesh_terms: D003941:Diagnostic Techniques, Ophthalmological; D015352:Dry Eye Syndromes / Q000175:diagnosis* / Q000378:metabolism; D005189:False Positive Reactions; D005260:Female; D006801:Humans; D008297:Male; D008537:Meibomian Glands / Q000502:physiology; D008875:Middle Aged; D009994:Osmolar Concentration; D011237:Predictive Value of Tests; D012372:ROC Curve; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013666:Tears / Q000502:physiology