title: Comparison of scleral and corneal Tono-Pen readings.
abstract: OBJECTIVE
  To compare scleral Tono-Pen (Medtronic Solan, Jacksonville, FL) readings to corneal Tono-Pen readings.
  
  
  METHODS
  Intraocular pressure (IOP) was measured prospectively in 72 eyes of 37 adult patients and in 10 eyes of 5 children. Measurements were taken on the central cornea and on the sclera. Recorded measurements were within 5% confidence levels by Tono-Pen.
  
  
  RESULTS
  Corneal IOP ranged from 10 to 28 mm Hg (mean +/- standard deviation, 17.0 +/- 3.8 mm Hg). Scleral measurements ranged from 4 to 99 mm Hg (40.4 +/- 23.0 mm Hg). Scleral measurements ranged from 11 mm Hg lower to 76 mm Hg higher than corneal measurements.
  
  
  CONCLUSIONS
  Tono-Pen readings obtained from sclera are of no clinical value and should not be used to approximate corneal IOP.
authors.affiliation: Veteran's Administration Los Angeles Outpatient Clinic, CA, USA.
authors.forename: Talia
authors.initials: T
authors.lastname: Kolin
authors.forename: Linda L
authors.initials: LL
authors.lastname: Wedemeyer
authors.forename: Elliot
authors.initials: E
authors.lastname: Kolin
authors.forename: Yosi
authors.initials: Y
authors.lastname: Braun
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D003315:Cornea / Q000502:physiology*; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology*; D008875:Middle Aged; D011446:Prospective Studies; D015203:Reproducibility of Results; D012590:Sclera / Q000502:physiology*; D014065:Tonometry, Ocular / Q000379:methods*