Comparison of IOP detected by three kinds of tenonometers in children with high intraocular pressure and their relations with corneal thickness

Abstract

AIM: To investigate the central corneal thickness(CCT)distribution of the children with ametropia in the non-contact tonometry(NCT), and the different intraocular pressure(IOP)measurements with Goldmann applanation tonometry(GAT)and the OCULUS Corvis ST(CST)corneal biomechanical analyzer, meanwhile, to evaluate the correlation between IOP and CCT. METHODS: NCT was used to measure 39 children(78 eyes)of non-glaucomatous ametropia with single eye or binocular IOP higher than 21 mmHg. The IOP was measured again with CST and GAT. The two instruments were measured in random order and the CCT was measured by CST and corrected the IOP according to the CCT. The eyes were divided into the normal group and the thicker group according to the CCT. The three IOP values were analyzed by the ANOVA, and the IOP and CCT was analyzed by the Pearson correlation coefficient. RESULTS: In the normal CCT group, the IOP by CST was lower than that the GAT and NCT measurements and the difference was statistically significant(F=5.12, P=0.01). In the thicker group, the comparison of the three intraocular pressure measurement methods was statistically significant(F=15.72, PrNCT=0.298, PNCT=0.04; rGAT=0.408, PGAT=0.01). There was no significant correlation between CST corrected intraocular pressure and CCT(rCST=0.062, PCST=0.593). CONCLUSION: The CCT of ametropia children with high IOP by Topcon tonometry were thicker. The corrected intraocular pressure of CST is lower than NCT and GAT. NCT and GAT were positively correlated with CCT. For children with thicker CCT, CST corrects intraocular pressure was closer to the real intraocular pressure value than NCT and GAT.

Keywords

• OCULUS corneal biomechanical analyzer
• Goldmann applanation tonometry
• non-contact tonometry
• central corneal thickness
• central corneal thickness