The Influence of Central Corneal Thickness and Corneal Curvature and Axial Length on the Measurement of Intraocular Pressure

Purpose: To examine the influence of central corneal thickness (CCT), cornealcurvature (CC), and axial length (AL) on intraocular pressure (IOP).Methods: Eighty-one clinically normal eyes were included in our study. The IOP, CCT,CC, AL were measured using a Goldmann applanation tonometer, optical pachymeter,keratometer and A-scan ultrasound biometer respectively in all subjects.Results: A highly significant positive correlation was identified between IOP and CCT.Linear regression analysis suggests that an increase in CCT of 0. 010 mm is associatedwith a 4. 946 mmHg increment in IOP. No significant positive correlation was identifiedbetween IOP and CC. P values are 0. 724 and 0. 414 respectively for vertical andhorizontal readings. A paradoxically reversed correlation was present between IOP andaxial length.Conclusion: Corneal thickness is a very important confounding factor in the measurementof intraocular pressure, which warrants further attention in our clinical practice. EyeScience 2002; 18: 176 - 18