Comparison of scleral and corneal Tono-Pen readings.
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.
Kolin
Talia
T
Veteran's Administration Los Angeles Outpatient Clinic, CA, USA.
Wedemeyer
Linda L
LL
Kolin
Elliot
E
Braun
Yosi
Y
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*