Comparison of three types of tonometers in healthy Indian eyes

Tonometry has evolved over centuries to find an ideal instrument to correctly measure IOP. Goldmann applanation tonometer (GAT) remains the gold standard for tonometry. The newer tonometers have been developed which operate without anaesthesia, fluorescein dye and with no or minimal contact. This non-interventional, cross-sectional study was done to know the agreement between three types of tonometers –Goldmann applanation tonometer, rebound tonometer (RT) and non-contact tonometry (NCT), in Indian eyes of healthy individuals. When compared to GAT, the measured IOP difference was found to be within ±3 mm Hg in two seventy-six eyes (84.6%; 95% CI: 80.6-88.5%) with RT, and in two eighty-one eyes (86.1%; 95% CI: 82.3-89.8%) with NCT. Both RT and NCT can be used as screening tools for IOP measurement in clinical practice within a relative range of IOP and CCT.