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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Extreme care was taken with all penetrationsof the eye to avoid touching the endothelium, the iris, or the lens. The ultrasonic CCT was measured after 15, 30,and 45 tonometdy of immersion.
Dynamic contour tonometry: principle and use.
Graefes Arch Clin Exp Ophthalmol. Institutional review board consentwas not considered necessary for this in vitro study, but departmental approvalwas obtained.
He disclosed no financial interest in the product and company mentioned herein. Ocular surface inflammatory changes induced by topical antiglaucoma drugs: However, its accuracy depends on many factors, including corneal thickness and other biomechanical properties.
DCT seems to be an appropriate method of tonometry for routine clinical use. The device seems to be particularly useful for IOP measurements in post-LASIK eyes 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. Similar findings have been reported by other researchers who have also noted that this effect persists even 3 months postoperatively.
Many of these individuals are undergoing the surgical modification of their corneas via LASIK and other techniques. As recommended by the manufacturer, only measurements of quality 3 or less were evaluated and included in the study. For that reason, accurate IOP is a fundamental variable in clinical practice.
The bottleheight was adjusted at 5 cm to begin each trial. Which image is in awareness during binocular rivalry? Sign in to make a comment Sign in to your personal account. Accuracy of Goldmann tonometry in clinical practice. Four eyes servedfor a preliminary study evaluating closed vs open stopcock systems, and theremaining 16 eyes were included in the main study and final analysis.
However, the promising advantages of DCT are the short learning curve, the ease of use of DCT in most patients in our experience, and the low intraobserver and interobserver variability because of semiautomatic recording. Dynamic contour tonometer DCT tip. Applanation tonometry is certainly knownto be influenced by corneal thickness.
The effect of corneal thickness on applanation tonometry. Furthermore, the corneal rigidity in patients with glaucoma may be altered primarily or secondarily to topical drugs, contou affecting IOP measurements, as some antiglaucomatous drugs may modulate the extracellular matrix. However, we dynamicc not subgroup patients with POAG tonometru to different medication use because of the heterogeneity of the drugs used and the statistical weakness of such stratification.
With manometric pressure used as the reference, DCT showed a slightabsolute deviation between 0.
Dynamic Contour Tonometry
Because the DCT can be attached to any slit lamp fitted with a normal GAT stand, the new tonometer can be used on most rigs without the need for modification. Dynamic contour tonometry and GAT intraocular pressure differences significantly increased with tonomdtry age slope, 0.
Pressure readings are sampled and digitized at Hz. Over the past four decades, Goldmann applanation tonometry GAT has become the standard for routine measurement of IOP, as the method has proven to be robust and easy to use with low intra- and interobserver variability.
In marked contrast, the DCT data were flat across the spectrum of corneal thickness readings, a finding that suggests that this tonometer alone functions independently of corneal thickness. Glaucoma Today delivers important information on recent research, surgical techniques, clinical strategies, and technology.
Copyright American Medical Association. Goldmann Applanation Tonometry in the Conscious Rat. Ehlers N, Hansen FK. Dynamic Contour Tonometry Overcoming the limitations of applanation tonometry. Sign in to vynamic your search Sign in to your personal account. tonometrj
In a prospective single-center study, consecutive patients with POAG were recruited from the glaucoma unit of the Department of Ophthalmology, University Hospital Basel, Basel, Switzerland, during a 6-month period between November 1,and April 30, Invest Ophthalmol Vis Sci.
Ophthalmologists are creating a pool of patients in whom a timely suspicion of glaucoma may be jeopardized by thinned or otherwise surgically altered corneas. The bottle heights were increased in contoyr increments up to a maximum of 75cm 58 mm Hg. B, Surface of the experimental DCT tip. Purchase access Subscribe to JN Learning for one year. The modeltreated cadavers and eyes honometry within cadavers as random effects and didnot assume equal variability in the 3 devices.
One hundred fifty healthy volunteers from the hospital staff with normal eyes on slit lamp examination and no history of previous ocular diseases, trauma, or surgery contributed eyes that were evaluated in a prospective single-center study. Statistical analysis was performed on computer SPSS statistical software, ver. At each bottle height, 5independent measurements of DCT, GAT, and PTG were made in randomized orderwith manometric pressure measured and recorded between each set of measurements.
The strongest correlationwas obtained in the range of 8 to 28 mm Hg with slopes of 0. Applanation tonometry and correction according to corneal thickness.
Dynamic contour tonometry: principle and use.
After application of topical anesthesia to the cornea, a paper stripe impregnated with fluorescein was used to stain the precorneal tear film immediately before IOP measurement. The dynamic contour tonometer DCT; Pascal tonometer is a novel tonometer designed to measure intraocular pressure IOP independent of corneal properties. In addition, patients with poor cooperation, poor quality of DCT readings, and unreliable measurements due to astigmatism greater than 2 diopters were also excluded.
It is possible that this slight inaccuracy may be due tochanges in the corneal curvature as the pressure becomes very high. In this study, we tried to address the issue of an open vs a closedstopcock system by using both methods in a preliminary study performed on4 human cadaver eyes defined by the same inclusion criteria as in the mainstudy.