Relationship between intraocular pressure and central corneal thickness in healthy people undergoing health check-ups

Abstract

Objective To investigate the distribution of intraocular pressure (IOP) and its relationship with central corneal thickness (CCT) in healthy people. Methods Participants included 1 715 persons undergoing health check-up during January 1 to December 31, 2018. They were enrolled according to the randomized digital table into this investigation by simple random sampling method; 879(51%) persons were male with an average age of 48.0±13.6 and 836 (49%) persons were female with an average age of 48.0±12.7. Participants were divided into different groups according to ten-year intervals. Each personal data, IOP and CCT were obtained; IOP was obtained by non-contact tonometer and CCT was obtained by optic coherence tomography. The data were analyzed by SPSS 25 statistical software. Results The average IOP in this study was 15.04±3.08 mmHg (1mmHg=0.133kPa) and the average CCT was 535.01±31.76 μm. The average IOP of each group showed an increase with age, and in the 50-59 years group it reached the highest level (15.47±3.11 mmHg), after which, it decreased again. The average CCT values in all groups decreased with ageing and the highest level was in the 18-30 years group (540±32.68 μm). The average IOP and CCT in males was higher than that in females. Multiple regression analysis adjusted for potential confounders such as age and gender implied that CCT is positively related to IOP (P<0.01). The IOP appeared to increase by 0.044 mmHg with the increase of every 1 mm of CCT (95%CI: 0.040~0.048，P<0.01). Conclusion IOP is closely related to CCT. More attention should be paid to CCT during the measurement of IOP to avoid misjudgment of a higher IOP for a higher CCT value as a pathological IOP or a pathological IOP among normal statistical range as a normal one, otherwise an opportunity for good treatment may be lost.