title: A noncontact pneumatic esthesiometer for measurement of ocular sensitivity: a preliminary report.
abstract: OBJECTIVE
  The aim of this investigation was to evaluate a prototype noncontact pneumatic esthesiometer for measuring sensitivity of the eye.
  
  
  METHODS
  To evaluate the instrument's repeatability, central corneal sensitivity was recorded on two separate occasions with a 24-h interval between the two measures. In a separate experiment, corneal edema was induced with a thick hydrogel lens, and the eye was closed and patched. Corneal sensitivity was measured before wearing the lenses for 3 h, immediately after lens removal, and 15 min later. Corneal sensitivity also was measured before the instillation of a single drop of proparacaine (Alcaine, 0.5%) and at 2 and 18 min later. Sensitivity was measured at the corneal apex and at a temporal conjunctival location 3 mm from the limbus.
  
  
  RESULTS
  A high correlation was found between days 1 and 2 (r = 0.90; p = 0.0001). The coefficient of repeatability (COR = 0.87 mm Hg) showed that 95% of the difference between test and retest measures were between +/-0.87 mm Hg. Corneal sensitivity decreased by 55% after lens-induced corneal swelling and by 159% after instillation of the topical anesthetic. Central corneal sensitivity was found to be significantly higher than that of the temporal conjunctiva (p = 0.0001).
  
  
  CONCLUSIONS
  We conclude that this pneumatic esthesiometer provides repeatable and reliable measures of ocular-surface sensitivity.
authors.affiliation: Centre for Contact Lens Research, School of Optometry, University of Waterloo, Ontario, Canada.
authors.forename: J A
authors.initials: JA
authors.lastname: Vega
authors.forename: T L
authors.initials: TL
authors.lastname: Simpson
authors.forename: D
authors.initials: D
authors.lastname: Fonn
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000779:Anesthetics, Local / Q000494:pharmacology; D003263:Contact Lenses, Hydrophilic; D003315:Cornea / Q000187:drug effects / Q000502:physiology* / Q000503:physiopathology; D015715:Corneal Edema / Q000209:etiology / Q000503:physiopathology; D004867:Equipment Design; D004864:Equipment and Supplies; D005123:Eye / Q000187:drug effects; D006801:Humans; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D008875:Middle Aged; D011430:Propoxycaine / Q000494:pharmacology; D015203:Reproducibility of Results; D012677:Sensation / Q000187:drug effects / Q000502:physiology*
chemical_list: D000779:Anesthetics, Local; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; C005717:proxymetacaine; D011430:Propoxycaine