Corneal parameters and difference between goldmann applanation tonometry and dynamic contour tonometry in normal eyes.
OBJECTIVE
To compare the difference between 2 methods of measuring the intraocular pressure (IOP), namely, Goldmann applanation tonometry (GAT) and dynamic contour tonometry (DCT) and to study the relationship with the corneal parameters in patients with no glaucoma signs.


METHODS
One hundred and eighteen eyes of 118 healthy subjects from 20 to 77 years of age underwent IOP measurements with DCT and GAT, central corneal thickness, and corneal volume measurements with Pentacam Scheimpflug camera. Pentacam examination has been performed first, then DCT and, after 10 minutes, GAT measurements.


RESULTS
The measurements with GAT ranged between 11 and 22 mm Hg (m=15.49+/-2.43 mm Hg), the measurements with DCT ranged between 10.5 and 25.1 mm Hg (m=17.59+/-2.9 mm Hg). DCT showed a statistically significant (P<0.0001) higher IOP measurement compared with GAT. A relation between differences in IOP with central corneal thickness and corneal volume was found, whereas no relation was found with corneal radius and age.


CONCLUSIONS
Our results show a discrete correlation between GAT and DCT measurements, but DCT showed slightly higher values of IOP. If DCT should be considered the gold standard, higher values of IOP could still be considered normal. These 2 devices cannot to be used interchangeably.
Lanza
Michele
M
Eye Department, Centro Grandi Apparecchiature, Second University of Naples, Naples, Italy.
Borrelli
Maria
M
De Bernardo
Maddalena
M
Filosa
Maria Luisa
ML
Rosa
Nicola
N
D000328:Adult; D000368:Aged; D000375:Aging / Q000502:physiology; D003315:Cornea / Q000033:anatomy & histology / Q000502:physiology*; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology*; D008875:Middle Aged; D010781:Photography / Q000379:methods; D011446:Prospective Studies; D015203:Reproducibility of Results; D014065:Tonometry, Ocular / Q000379:methods*