Clin Exp Ophthalmol. Dec;34(9) Dynamic contour tonometry: principle and use. Punjabi OS(1), Kniestedt C, Stamper RL, Lin SC. The PASCAL Dynamic Contour Tonometer (DCT) from Ziemer is a slitlamp mounted tonometer for measuring intraocular pressure IOP independent of corneal. The gold standard for assessing IOP is Goldmann applanation tonometry (GAT). Recently, the dynamic contour tonometer (DCT) has become.

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Exposing a miniaturized pressure sensor closely to the contour of such a cornea is thought to measure IOP directly i.

Neither CCT, corneal curvature, corneal astigmatism, anterior contur depth, nor axial length had a significant influence on pressure readings by DCT. We use cookies to offer a better user experience and to analyze site traffic. Create a free personal account to make a comment, download free article PDFs, sign up for alerts and more. Dynamic contour tonometry and GAT intraocular pressure differences significantly increased with older age slope, 0.

Glaucoma Today – Dynamic Contour Tonometry (March/April )

Falsely elevated intraocular pressure due to increased central corneal thickness. The isotonic sodium chloride solution infusion bottle was attachedto an electrically driven intravenous pole for bottle height adjustment Figure 2. Previous studies have shown IOP readings to decrease with successive GAT measurements, but this effect is absent in the case of rapid repetition of IOP measurements by the same examiner, as in the present study. Graefes Arch Clin Exp Ophthalmol.


The effect of corneal thickness on applanation tonometry. Performing applanation tonometry with the GAT on cadaver eyes is challengingand fraught with potential for error.

Copyright Tonlmetry Medical Association. Furthermore,the data show little difference in results between open and closed stopcockmethods. Human corneal thickness and its impact on intraocular pressure measures: The Ocular Hypertension Treatment Study: It is possible that this slight inaccuracy may be due tochanges in the corneal curvature as the pressure becomes very high.

The FDA has approved the instrument for use in humans. Corneal thickness, corneal curvature, astigmatism, anterior chamber depth, and axial length were entered as continuous independent variables.

The stopcock at the gauge needle tube was closed atthe maximal IOP and the globe was left in the cadaver eye holder but unhookedfrom the reservoir bottle distal to the stopcock. Most studies have contuor pressures or some kind of algorithm to peg the manometric pressure. Extreme care was taken with all penetrationsof the eye to avoid touching the endothelium, the iris, or the lens. The ages ofthe cadavers ranged from 64 to 84 years. Privacy Policy Terms of Use.

Dynamic Contour Tonometry

Other studies 68 – 10 found that patients with normal-tension glaucoma have thinner corneas than those of the general population. See More About Glaucoma Ophthalmology. Over the past four decades, Goldmann applanation tonometry GAT has become the contoru for routine measurement of IOP, as the method has proven to be robust and easy to use with low intra- and interobserver variability.

The device seems to be particularly useful for IOP measurements in post-LASIK contout as well as in other corneas that are thinner or thicker than average and in which the practitioner cannot achieve accurate readings by force tonometry.


Comparison of Dynamic Contour Tonometry with Goldmann Applanation Tonometry | IOVS | ARVO Journals

After the experiment, the bottle height was lowered to theinitial 5 cm. Other tonometers, such as the pneumatonometer PTG2324 theMcKay-Marg tonometer, and its derivative, the handheld tonometer Tono-Pen;Mentor, Norwell, Masshave been reported to be more accurate, especiallyin corneas outside the average in thickness. Sign in to make a comment Sign in to your personal account.

Corneal thickness in ocular hypertension, toometry open-angle glaucoma, and normal-tension glaucoma.

The contoured tip features a concave surface with a radius of Mixed-effects models incorporated fixed and random effects. KaufmannNone; L.

Dynamic contour tonometry: principle and use.

Forcing thecentral area of the cornea into the contour of the DCT tip allows the examinerto measure the pressure of the eye directly and continuously on the externalsurface of the cornea. Univariate linear regression using DCT as the dependent variable and GAT as the independent variable gives a slope of 0. Controversy exists regarding the method to manometrically measure IOPin cadaver eyes. To evaluate intra- and interobserver variability, IOP was measured in eight eyes by four observers.