Abstract
Aim and Objective: To study the prevalence and variability of calibration errors in Goldmann applanation Tonometer’s.
Methods: 53 Goldmann applanation tonometers were checked with standard calibration error check weight bar, by two independent observers and classified into 6 categories of ±0.5,±1,±1.5,±2,±2.5 and >±2.5 mmHg.
Results: There were 30(57%),17(32%),1(2%),3(5%),0(0%) and 2(4%) with calibration errors of ±0.5,±1,±1.5,±2,±2.5 and >±2.5 mmHg respectively with good agreement between observers.
Conclusion: Study showed significant calibration error prevalence & variability in tonometers. Further studies required to establish the frequency of calibration, and to evaluate the relationship between calibration errors and clinical errors in IOP measurement.