Purchase this article with an account.
S. Lautebach, M. Pache, S. Wilmsmeyer, J. Funk; Dynamic Contour Tonometry versus Goldmann Tonometry – A Comparative Study . Invest. Ophthalmol. Vis. Sci. 2005;46(13):4842.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Purpose: A potential dependency of Goldmann Applanation Tonometry (GAT) values on Central Corneal Thickness (CCT) is increasingly discussed. The newly developed Dynamic Contour Tonometry (DCT) is supposed to measure intraocular pressure (IOP) independently of CCT. We compared the dependence of CCT for both GAT and DCT values. Methods: In a first study, we measured IOP (DCT and GAT) and CCT (Orbscan) in the right eye of 103 subjects. The difference DCT minus GAT was calculated and plotted versus CCT to assess a possible linear correlation. In a second study, we measured IOP (DCT and GAT) in both eyes of those subjects who participated in the first sudy and showed a difference > 2 mmHg between DCT and GAT. Results: Patients with higher CCT values showed a tendency towards higher IOP values when measured by GAT. This finding however, did not reach statistical significance. A difference > 2 mmHg between DCT and GAT was present in 39 subjects. In a second examination a few weeks later, we found this difference to be reproducible in the same eye in 66%. 76% of all patients having such a reproducible difference > 2 mm Hg in the first eye showed a difference > 1.5 mmHg in the contralateral eye. Conclusions: As might be expected if GAT values depend on CCT, we found the difference GAT–DCT to increase with higher CCT values. The effect, however, was non–significant. Our second study showed that, in subjects with a great difference between DCT and GAT values, this difference was reproducible. Moreover, we found a comparable difference in the contralateral eye of these subjects. We therefore speculate that, apart from CCT, other not yet identified features of the human cornea might influence the results of IOP measurements.
This PDF is available to Subscribers Only