REPRODUCIBILITY OF INTRAOCULAR-PRESSURE AND OUTFLOW FACILITY MEASUREDBY PNEUMATIC TONOGRAPHY AND SCHIOTZ TONOGRAPHY

The purpose of this study was to compare means, variability, and repro ducibility in intraocular pressure and in outflow facility measured re peatedly over several days by Bio-Rad pneumatonography and Schiotz ton ography in normal human volunteers. For each instrument a measurement of intraocular pressure and one of outflow facility were obtained at e ach of three repeated examinations of eight healthy subjects in the su pine position. For pressure, the Bio-Rad mean was significantly higher by 5.31 mmHg than the Schiotz mean (p < 0.00005). Reproducibility was 71.1% and 59.0% for the Bio-Rad and Schiotz, respectively. For outflo w, the Bio-Rad and Schiotz means were not significantly different. Rep roducibility was 17.3% and 58.7% for the Bio-Rad and Schiotz, respecti vely. For measuring pressure, both the Bio-Rad and Schiotz instruments had good reproducibility; for measuring outflow, the Bio-Rad and Schi otz instruments had low and good reproducibility, respectively.