Purpose:
1) To evaluate intra and inter observer reproducibility of intraocular pressure (IOP) estimates obtained using the Diaton transpalpebral tonometer (DTT) and 2) to compare it to other clinical tonometers the Goldmann applanation Tonometer (GAT), Pascal Dynamic Contour Tonometer (DCT) and Ocular Response Analyzer (ORA)
Methods:
Sixty eyes of sixty individuals were prospectively evaluated for the study and measurements were obtained using the DTT twice by two trained observers (BM and KD) in a random sequence (mean age 29.4, M/F =26/34). Seventy nine eyes of seventy nine subjects were additionally examined and measurements were obtained in a random sequence with two minute time interval using the DTT, GAT, DCT and ORA for the purposes of comparison of tonometer study (mean age 33.29; M/F= 36/43). The Altmann and Bland analysis was performed to evaluate inter and intra observer reproducibility of DTT and compare the IOP estimates obtained by various tonometers.
Results:
The mean IOP obtained using various tonometers is given Table 1. The 95% limits of agreement of intra-observer reproducibility in measuring IOP using the DTT for BM and KD was -4.6 to +4.6 and -6.3 to +5.9 mmHg respectively. The 95% limits of agreement of inter- observer reproducibility in measuring IOP using the DTT was -6.6 to +7.7 and -7.0 to +7.8 mmHg. The 95% limits of agreement between IOP estimates of DTT and IOP estimates of the GAT , DCT and ORA were large and also there was significant bias in estimates of IOP obtained using the diatom always being lower than the other tonometers (Table 2)
Conclusions:
The limits of agreement between various clinical tonometers and DTT is wide and thus IOP estimates obtained using the DTT has to be cautiously interpreted.
Keywords: intraocular pressure • clinical (human) or epidemiologic studies: systems/equipment/techniques • clinical laboratory testing