Dynamic Contour Tonometry, Tono-Pen XL®, and Goldmann Applanation Tonometry in Comparison to Intracameral Intraocular Pressure (IOP) Measurements in Patients with Corneal Pathologies


Purpose: The accuracy of Goldmann applanation tonometry (GAT) has been shown to depend on several biomechanical properties of the cornea. Newer tonometry devices (e.g., the Dynamic Contour Tonometer PASCAL? [DCT] and the Tono-Pen? XL [TP]) have been designed to accurately measure intraocular pressure (IOP) independent of corneal thickness (CCT) and pathology. This study investigates the influence of corneal pathologies on the accuracy of these IOP measuring devices, and compares this accuracy to that of direct intracameral IOP measurement. Methods: 8 eyes of 8 patients suffering from corneal pathologies scheduled for penetrating keratoplasty, and 10 eyes of 10 patients scheduled for cataract surgery (control group) were examined. Before surgery, the anterior chamber was cannulated at the temporal corneal limbus. In a closed system, the intraocular pressure (IOP) was directly set to 10, 20, and 30 mmHg with a manometric water column. Intraocular pressure measurements taken by GAT, DCT, and TP were compared to intracameral measurements obtained by a precision reference pressure sensor. Results: Control group: All three methods showed good agreement with the intracameral readings (mean deviation of all three devices, -0.9 mmHg). Group with corneal pathologies: The TP yielded the most exact IOP values in the group with corneal pathologies when taking all diagnoses into account. The mean deviations from the intracameral IOP measurements were -0.9 mmHg ± 3.2 mmHg (mean ± SD) for TP, -2.9 mmHg ± 3.3 mmHg for GAT, and -5.0 mmHg ± 7.9 mmHg for DCT. For bullous keratopathy, the most exact IOP readings were obtained by the TP (mean deviation -0.2 mmHg ± 3.5 mmHg). The TP and GAT devices underestimated IOP in the patients with Fuchs’ endothelial dystrophy; all 3 devices underestimated adjusted IOP after keratoplasty. DCT showed the greatest deviations from adjusted IOP in the case of non-herpetic scars. In the control group, none of the devices showed a statistically relevant dependency on CCT. Nevertheless, in the group with corneal pathologies, only TP showed no dependency on CCT. Conclusion: Our results suggest that the Tono-Pen XL? is the most accurate measurement device to determine IOP in patients with corneal pathologies, especially in patients suffering from corneal edema (bullous keratopathy). GAT yielded surprisingly exact IOP values in patients suffering from irregular corneal surface. DCT showed a high degree of deviation from the adjusted IOP, and should not be used to determine IOP in corneas with the disorders listed here.

Share and Cite:

Neuburger, M. , Großwendt, J. , Lautebach, S. , Maier, P. , Birnbaum, F. , Böhringer, D. , Funk, J. , Jordan, J. and Reinhard, T. (2014) Dynamic Contour Tonometry, Tono-Pen XL®, and Goldmann Applanation Tonometry in Comparison to Intracameral Intraocular Pressure (IOP) Measurements in Patients with Corneal Pathologies. Open Journal of Ophthalmology, 4, 46-55. doi: 10.4236/ojoph.2014.42009.

Conflicts of Interest

The authors declare no conflicts of interest.


[1] Goldmann, H. and Schmidt, T. (1957) Applanation Tonometry. Ophthalmologica, 134, 221-242.
[2] Ehlers, N., Bramsen, T. and Sperling, S. (1975) Applanation Tonometry and Central Corneal Thickness. Acta Ophthalmol (Copenh), 53, 34-43.
[3] Whitacre, M.M. and Stein, R. (1993) Sources of Error with Use of Goldmann-Type Tonometers. Survey of Ophthalmology, 38, 1-30.
[4] Whitacre, M.M., Stein, R.A. and Hassanein, K. (1993) The Effect of Corneal Thickness on Applanation Tonometry. American Journal of Ophthalmology, 115, 592-596.
[5] Oh, J., Yoo, C., Kim, Y.Y., Kim, H. and Song, J. (2009) The Effect of Contact Lens-Induced Corneal Edema on Goldmann Applanation Tonometry and Dynamic Contour Tonometry. Graefe’s Archive for Clinical and Experimental Ophthalmology, 247, 371-375.
[6] Simon, G., Small, R.H., Ren, Q. and Parel, J.M. (1993) Effect of Corneal Hydration on Goldmann Applanation Tonometry and Corneal Topography. Refractive Corneal Surgery, 9, 110-117.
[7] Reinhard, T. and Sundmacher, R. (1999) Determining Real IOP Values. Journal of Cataract & Refractive Surgery, 25, 157-158.
[8] Madjlessi, F., Marx, W., Reinhard, T., Althaus, C. and Sundmacher, R. (2000) Impression and Applanation Tonometry in Irregular corneas. Comparison with Intraocular Needle Tonometry. Ophthalmologe, 97, 478-481.
[9] Marx, W., Madjlessi, F., Reinhard, T., Althaus, C. and Sundmacher, R. (1999) More than 4 Years’ Experience with Electronic Intraocular Needle Tonometry. Ophthalmologe, 96, 498-502.
[10] Boehm, A.G., Weber, A., Pillunat, L.E., Koch, R. and Spoerl, E. (2008) Dynamic Contour Tonometry in Comparison to Intracameral IOP Measurements. Investigative Ophthalmology & Visual Science, 49, 2472-2477.
[11] Kniestedt, C. and Kanngiesser, H.E. (2006) Dynamic Contour Tonometry. Ophthalmologe, 103, 713-721.
[12] Frenkel, R.E., Hong, Y.J. and Shin, D.H. (1988) Comparison of the Tono-Pen to the Goldmann Applanation Tonometer. Archives of Ophthalmology, 106, 750-753.
[13] Reinhard, T., Kallmann, C., Cepin, A., Godehardt, E. and Sundmacher, R. (1997) The Influence of Glaucoma History on Graft Survival after Penetrating Keratoplasty. Graefe’s Archive for Clinical and Experimental Ophthalmology, 235, 553-557.
[14] Barleon, L., Hoffmann, E.M., Berres, M., Pfeiffer, N. and Grus, F.H. (2006) Comparison of Dynamic Contour Tonometry and Goldmann Applanation Tonometry in Glaucoma Patients and Healthy Subjects. American Journal of Ophthalmology, 142, 583-590.
[15] Pache, M., Wilmsmeyer, S., Lautebach, S. and Funk, J. (2005) Dynamic Contour Tonometry versus Goldmann Applanation Tonometry: A Comparative Study. Graefe’s Archive for Clinical and Experimental Ophthalmology, 243, 763-767.
[16] Pepose, J.S., Feigenbaum, S.K., Qazi, M.A., Sanderson, J.P. and Roberts, C.J. (2007) Changes in Corneal Biomechanics and Intraocular Pressure Following LASIK Using Static, Dynamic, and Noncontact Tonometry. American Journal of Ophthalmology, 143, 39-47.
[17] Francis, B.A., Hsieh, A., Lai, M., Chopra, V., Pena, F., Azen, S. and Varma, R. (2007) Effects of Corneal Thickness, Corneal Curvature, and Intraocular Pressure Level on Goldmann Applanation Tonometry and Dynamic Contour Tonometry. Ophthalmology, 114, 20-26.
[18] Viestenz, A., Langenbucher, A. and Viestenz, A. (2006) Reproducibility of Dynamic Contour Tonometry. Comparison with TonoPenXL and Goldmann Applanation Tonometry—A Clinical Study on 323 Normal Eyes. Klinische Monatsblätter für Augenheilkunde, 223, 813-819.
[19] Viestenz, A., Langenbucher, A., Seitz, B. and Viestenz, A. (2006) Evaluation of Dynamic Contour Tonometry in Penetrating Keratoplasties. Ophthalmologe, 103, 773-776.
[20] Amaral, W.O.G., Teixeira, R.M.B., Alencar, L.M., Cronemberger, S. and Calixto, N. (2006) Central and Peripheral Corneal Thickness: Influence on the Iop Measurement by Tonopen. Arquivos Brasileiros de Oftalmologia, 69, 41-45.
[21] Bhan, A., Browning, A.C., Shah, S., Hamilton, R., Dave, D. and Dua, H.S. (2002) Effect of Corneal Thickness on Intraocular Pressure Measurements with the Pneumotonometer, Goldmann Applanation Tonometer, and Tono-Pen. Investigative Ophthalmology & Visual Science, 43, 1389-1392.
[22] Midelfart, A. and Wigers, A. (1994) Clinical Comparison of the ProTon and Tono-Pen Tonometers with the Goldmann Applanation Tonometer. British Journal of Ophthalmology, 78, 895-898.
[23] Iester, M., Mermoud, A., Achache, F. and Roy, S. (2001) New Tonopen XL: Comparison with the Goldmann Tonometer. Eye, 15, 52-58.
[24] Rao, V.J., Gnanaraj, L., Mitchell, K.W. and Figueiredo, F.C. (2001) Clinical Comparison of Ocular Blood Flow Tonometer, Tonopen, and Goldmann Applanation Tonometer for Measuring Intraocular Pressure in Postkeratoplasty Eyes. Cornea, 20, 834-838.
[25] Shemesh, G., Waisbourd, M., Varssano, D., Michaeli, A., Lazar, M. and Kurtz, S. (2009) Measurements of Intraocular Pressure by Goldmann Tonometry, Tonopen XL, and the Transpalpebral Tonometer, TGDc-01, after Penetrating Keratoplasty: A Comparativye Study. Cornea, 28, 724-727.
[26] Kaufmann, C., Bachmann, L.M. and Thiel, M.A. (2003) Intraocular Pressure Measurements Using Dynamic Contour Tonometry after Laser in Situ Keratomileusis. Investigative Ophthalmology & Visual Science, 44, 3790-3794.
[27] Kohlhaas, M., Boehm, A.G., Spoerl, E., Pürsten, A., Grein, H.J. and Pillunat, L.E. (2006) Effect of Central Corneal Thickness, Corneal Curvature, and Axial Length on Applanation Tonometry. Archives of Ophthalmology, 124, 471-476. http://dx.doi.org/10.1001/archopht.124.4.471

Copyright © 2022 by authors and Scientific Research Publishing Inc.

Creative Commons License

This work and the related PDF file are licensed under a Creative Commons Attribution 4.0 International License.