Influence of central corneal thickness on intraocular pressure measured with three tonometers

Objective To evaluate the influence of central corneal thickness(CCT)on intraocular pressure(IOP)values measured with Icare rebound tonometer(Icare),Goldmann applanation tonometer(GAT)and PASCAL dynamic contour tonometer(DCT).Methods CCT and IOP were measured in 152 eyes of 78 cases.IOP measurement was performed on each eye with Icare,GAT and DCT.The IOP values with three tonometers under different CCT were compared,and the relations between IOP and CCT were analyzed.Results The mean IOP values measured with Icare,GAT and DCT were(19.16±5.03)mmHg(1 kPa=7.5 mmHg),(18.41±4.52)mmHg and(17.23±3.69)mmHg respectively.There was significant difference among Icare,GAT and DCT(F=7.256,P=0.001).IOP values detected with Icare and GAT had positive correlation with CCT(r=0.341,P0.001;r=0.333,P0.001).When CCT changed 10 μm,IOP of Icare changed 0.47 mmHg,the IOP of GAT changed 0.41 mmHg;While the correlation between IOP values of DCT and CCT was quite opposite(r=0.032,P=0.699).Conclusions The IOP values measured with Icare and GAT show a significant dependency on CCT,whereas Icare is more dependent on CCT than GAT.IOP values measured with DCT shows no significant dependency on CCT.