Clinical comparison of two intraocular pressure measurement methods: SmartLens dynamic observing tonography versus Goldmann

Troost, Raphael; Vogel, Annette; Beck, Stefanie; Schwenn, Oliver; Grus, Franz H.; Pfeiffer, Norbert

doi:10.1007/s00417-001-0376-4

Cited by 12 publications

(10 citation statements)

References 19 publications

(15 reference statements)

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“…They have all been compared with the Goldmann applanation tonometer, which has been considered the gold standard. [1][2][3] When comparing tonometry devices randomisation of methods is necessary because each subsequent measurement lowers the IOP by 0.1-0.4 mm Hg. 4 5 A new tonometry method needs to be accurate and reproducible.…”

Section: Discussionmentioning

confidence: 99%

Transpalpebral tonometry: reliability and comparison with Goldmann applanation tonometry and palpation in healthy volunteers

Troost¹

2005

British Journal of Ophthalmology

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Background/aim: TGDc-01 is a new, portable, transpalpebral tonometry device. The aim of this study was to evaluate the reproducibility of this method, including intraobserver and interobserver deviations, and to compare the results with those of Goldmann applanation tonometry and palpation of intraocular pressure (IOP). Methods: A total of 40 eyes of 20 healthy volunteers were included. Two independent parallel observers (1 and 2) performed three replicate measurements per eye, respectively, both using TGDc01 tonometry, one observer (3) performed three replicate measurements using Goldmann applanation tonometry, and one observer (4) measured the IOP via palpation. Intraindividual deviations within and between both observers using TGDc-01 tonometry and between all three methods were investigated about clinically relevance by comparison of medians and quartiles, statistically significance by pairwise sign tests. Comparisons between observers and methods were based on averaged IOP values of the three individual measurements for each observer and each patient. Intraobserver deviations were analysed by means of Friedman tests. Results: Observers 1 and 2 showed a statistically significant intraobserver deviation when using TGCc-01 (Friedman p = 0.007 for observer 1 and p = 0.002 for observer 2). There was no statistically significant interobserver deviation between observers 1 and 2 (sign test p = 0.200); however, in 45% of the eyes interobserver deviations were larger than plus or minus 3 mm Hg. The median intraindividual deviation between TGDc-01 and Goldmann (TGDc-01 minus Goldmann) was 0 mm Hg (interquartile range 21; 2 mm Hg; sign test p = 0.522); but deviations were larger than plus or minus 3 mm Hg for 38% of the 40 eyes. Median intraindividual deviation between TGDc-01 and palpation (TGDc-01 minus palpation) was 22 mm Hg (interquartile range 24; 1 mm Hg; sign test p = 0.018), but deviations were larger than plus or minus 3 mmHg for 43% of eyes. Median intraindividual deviation between Goldmann and palpation (palpation minus Goldmann) was 2 mm Hg (interquartile range 22; 4 mm Hg; p = 0.429), but deviations were larger than plus or minus 3 mm Hg in 48% of the eyes. Conclusion: Interobserver deviations using TGDc-01 tonometry and intraindividual deviations between TGDc-01 tonometry, Goldmann applanation tonometry, and palpation of IOP were found to be clinically relevant. Thus, according to our results TGDc-01 could not be established as a substitute or diagnostic alternative method for Goldmann applanation tonometry. But as deviations between TGDc01 and Goldmann turned out smaller than between palpation of IOP and Goldmann, TGDc-01 seems to provide a better choice for tonometry in patients, in whom Goldmann applanation tonometry is not possible.

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Section: Discussionmentioning

confidence: 99%

Transpalpebral tonometry: reliability and comparison with Goldmann applanation tonometry and palpation in healthy volunteers

Troost¹

2005

British Journal of Ophthalmology

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“…A reduction of the blood flow may cause hypoxia and further cell death and therefore may also initiate diseases like glaucoma and maybe other circulatory problems. In different studies the effect of local glaucoma therapy on ocular hemodynamics is determined using different instruments for IOP- and OPA-measurements [4,6-15]. …”

Section: Introductionmentioning

confidence: 99%

Intraocular pressure and ocular pulse amplitude using dynamic contour tonometry and contact lens tonometry

Hoffmann¹,

Grus²,

Pfeiffer³

2004

BMC Ophthalmol

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BackgroundThe new Ocular Dynamic Contour Tonometer (DCT), investigational device supplied by SMT (Swiss Microtechnology AG, Switzerland) allows simultaneous recording of intraocular pressure (IOP) and ocular pulse amplitude (OPA). It was the aim of this study to compare the IOP results of this new device with Goldmann tonometry. Furthermore, IOP and OPA measured with the new slitlamp-mounted DCT were compared to the IOP and OPA measured with the hand-held SmartLens®, a gonioscopic contact lens tonometer (ODC Ophthalmic Development Company AG, Switzerland).MethodsNineteen healthy subjects were included in this study. IOP was determined by three consecutive measurements with each of the DCT, SmartLens®, and Goldmann tonometer. Furthermore, OPA was measured three times consecutively by DCT and SmartLens®.ResultsNo difference (P = 0.09) was found between the IOP values by means of DCT (mean: 16.6 mm Hg, median: 15.33 mm Hg, SD: +/- 4.04 mm Hg) and Goldmann tonometry (mean: 16.17 mm Hg, median: 15.33 mm Hg, SD: +/- 4.03 mm Hg). The IOP values of SmartLens® (mean: 20.25 mm Hg, median: 19.00 mm Hg, SD: +/- 4.96 mm Hg) were significantly higher (P = 0.0008) both from Goldmann tonometry and DCT. The OPA values of the DCT (mean: 3.08 mm Hg, SD: +/- 0.92 mm Hg) were significantly lower (P = 0.0003) than those obtained by SmartLens® (mean: 3.92 mm Hg, SD: +/- 0.83 mm Hg).ConclusionsDCT was equivalent to Goldmann applanation tonometry in measurement of IOP in a small group of normal subjects. In contrast, SmartLens® (contact lens tonometry) gave IOP readings that were significantly higher compared with Goldmann applanation tonometer readings. Both devices, DCT and SmartLens® provide the measurement of OPA which could be helpful e.g. for the management of glaucoma.

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“…2,3 Goldmann believed that as long as the applanated area had a diameter of 3.06 mm (area of 7.354 mm 2 ) normal corneal variations in man did not influence the instrument's reading: 'It does not make any difference if the cornea is more curved or less, or if the eye has a higher or lower rigidity'. 4,5 Since then, however, it has been shown that the tonometer's recordings are affected by a number of normal variations of the globe, such as corneal thickness, 6 corneal curvature, 7 and axial length.…”

Section: Introductionmentioning

confidence: 99%

Corneal astigmatism in applanation tonometry

Mark

2003

Eye

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Purpose This short study aims at quantitatively correlating scale readings of the Goldmann tonometer to corneal curvatures in one and the same eye. Methods A total of 30 eyes of 21 adult patients who presented themselves in clinical practice for routine examination were arbitrarily selected. Corneal curvatures were measured in the horizontal and vertical meridians and then applanation tension measured in the same order. The data were submitted to statistical analysis by computer using Microsoft Excel and SAS System programs. Results All cases exhibited a strong positive correlation of tonometric readings to corneal curvature, that is, the flatter the curvature, the lower the reading on the scale of the tonomer, and vice versa. Conclusion The numbers on the scale of the Goldmann tonometer may not represent true intraocular pressure in mmHg because their values depend on a number of variables of the globe, including corneal astigmatism. Attention to these influences may help interpret the tonometric record in difficult cases.

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Clinical comparison of two intraocular pressure measurement methods: SmartLens dynamic observing tonography versus Goldmann

Cited by 12 publications

References 19 publications

Transpalpebral tonometry: reliability and comparison with Goldmann applanation tonometry and palpation in healthy volunteers

Transpalpebral tonometry: reliability and comparison with Goldmann applanation tonometry and palpation in healthy volunteers

Intraocular pressure and ocular pulse amplitude using dynamic contour tonometry and contact lens tonometry

Corneal astigmatism in applanation tonometry

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