PURPOSE: To compare intraocular pressure (IOP) readings of Goldmann applanation tonometry (GAT) and dynamic contour tonometry (DCT), and to correlate central corneal thickness (CCT) with these readings. METHODS: This transversal study included patients in two groups: open-angle glaucoma (OAG) and normal eyes (NE). IOP measurements were obtained in all patients using GAT and DCT. The same examiner made all GAT measurements. Another examiner, who was masked to the GAT readings, made DCT measurements. CCT was determined by ultrasound pachimetry. RESULTS: The study included 134 eyes of 71 subjects. The groups were composed of 85 eyes from 45 patients with OAG and 49 eyes from 26 subjects with NE. There was no statically significant difference between CCT in the two groups (p = 0,54, right eye; p = 0,71, left eye). DCT readings consistently were higher than GAT measurements in the two groups (OAG: p < 0,001; NE: p = 0,01). There was good correlation between GAT and DCT in both groups (p < 0,001). Neither GAT nor DCT showed a significant correlation with CCT, except in the separate analysis of all right eyes (p = 0,03; r² = 0,07). Bland-Altman graphs showed disagreement between GAT and DCT. CONCLUSION: Measurements with both GAT and DCT were not correlated with CCT. The agreement between GAT and DCT were not good. The IOP measurements by GAT were lower when compared with DCT. DCT readings seem to be less dependent on CCT than TAG readings.
Glaucoma, open-angle; Intraocular pressure; Diagnostic techniques, ophthalmological; Tonometry, ocular; Case-control studies
