[Comparison of dynamic contour tonometry versus Goldmann applanation tonometry according to the International Ocular...

The aim of this study was to compare the dynamic contour tonometry PASCAL® (DCT) versus the Goldmann applanation tonometry (GAT) in a glaucoma population and to analyse the correlation with the central corneal thickness (CCT).

191 eyes of 107 Caucasian glaucoma patients (62 female, 45 male) were included: 3 repeated GAT and dynamic contour tonometry (DCT) measurements (quality factor 1-2) were analysed. CCT was measured by ultrasound pachymetry. Criteria of ISO 8612 were fulfilled: 3 groups of IOP measurements were formed: group 1: 7-16 mmHg, group 2: 16-23 mmHg and group 3: > 23 mmHg, each including at least 40 eyes. Only 5.0 % outliers per area of intraocular pressure were permitted in a tolerance of ± 5.0 mmHg.

Data of 191 eyes (mean CCT 553 µm) were analysed. GAT (19.68 mmHg ± 7.56 mmHg) showed good correlation to DCT (20.54 ± 8.21 mmHg) (r = 0.770, p < 0.001). Mean difference DCT-GAT was 0.86 ± 2.45 mmHg. In regard to the criteria of ISO 8612, the number of outliers were: group 1: (n = 68) 29.4 %, group 2: (n = 62) 41.9 %, and group 3: (n = 61) 31.2 %. No correlation was shown between CCT vs. GAT (r = 0.184, p = 0.057) and CCT vs. DCT (r = 0.177, p = 0.09), respectively.

In conclusion, despite good correlation to GAT measurements DCT does not fulfil the ISO 8612 reference criteria in glaucoma patients. DCT and GAT did not show correlation to CCT.