Correlation of central corneal thickness and intraocular pressure in myopic eyes

AbstrcatObjectiveTo evaluate the relationship between central corneal thickness(CCT) and intraocular pressure(IOP) in myopic eyes and it's clinical significance.MethodsThe CCT were measured by ultrasonic and IOP by noncontact tonometer in 1 264 eyes of 659 myopic patients, the data were analysed statistically.ResultsTook CCT as X and IOP as Y, then a linear regression formula Y=-2.3633+0.0347X was concluded (P0.01). 1 264 eyes were divided into four groups according to their CCT: groupⅠ CCT: 486.18μm±12.10μm; groupⅡCCT: 52769μm±1304μm; group ⅢCCT: 568.87μm±13.11μm and group Ⅳ CCT: 612.25μm±11.07μm, the IOPs of four groups were 14.34mmHg±2.48mmHg(1kPa=7.5mmHg), 1596mmHg±2.70mmHg, 17.45mmHg±2.39mmHg and 1848mmHg±2.41mmHg respectively. There was significant difference between each pair of groups (P0.01). While all cases were divided into four groups according to refractive power (diopter): groupⅠ2.26D±0.14D, groupⅡ 4.53D±0.87D, group Ⅲ 7.29D±0.91D and group Ⅳ 12.75D±3.53D,the IOPs of four groups were 16.45mmHg±2.48mmHg, 16.52mmHg±2.75mmHg, 16.57mmHg±2.83mmHg and 16.80mmHg±2.66mmHg respectively. There was no significant difference between each pair of groups (P0.05).ConclusionThere is a significant positive correlation between CCT and IOP in myopic eyes while there is no correlation between IOP and myopic diopter. The CCT is an important factor to affect the reading of IOP. Finding out CCT is helpful in evaluating IOP correctly and distinguishing some eye diseases.