Abstract
Introduction: :
Aim: To investigate the variation of corneal hysteresis (CH) and its ocular and systemic associations in normal Chinese subjects
Methods: :
Consecutive Chinese subjects aged 40 years and older participating in the Singapore Chinese Cohort Eye Study (SICC) study, a population based cross-sectional study of eye diseases were enrolled in this study. All subjects underwent a complete ocular examination including intra-ocular pressure (IOP) measurement by Goldmann applanation tonometry (GAT), refraction and keratometry. Corneal hysteresis (CH), corneal resistance factor (CRF), corneal compensated intraocular pressure (IOPcc) were measured in the right eye of all subjects with the Ocular Response Analyzer (ORA; Reichert Ophthalmic Instruments, Buffalo, NY). Central corneal thickness (CCT), axial length (AXL) and anterior chamber depth were also measured.
Results: :
658 consecutive Chinese subjects with a mean age of 54.76 ± 8.19 years were included in the analysis. 51.5 % were females. Mean CH was 10.64 ± 1.47 (range, 5.90 - 16.17) mmHg and females were noted to have higher mean CH than males (CH males vs female: ß = 0.62; p<0.001). CH was found to decrease with increasing age (ß =-0.04, p < 0.001) and this relationship persisted after adjusting for gender. In multivariate analysis adjusted for age/gender and other measured variables, CH was associated with IOP-GAT (ß=0.29;p<0.001), IOPcc (ß= -0.52;p<0.001) and CRF(ß= 0.52;p<0.001) but was not associated with spherical equivalent (p=0.42), keratometry (p=0.46), ACD (p=0.65),CCT (p=0.37) or AXL (p=0.73).There was also no association between CH with diabetes (p=0.71), hypertension(p= 0.31) or body mass index (BMI, p=0.68).
Conclusions: :
CH in normal adult Chinese decreases with age and was associated with IOP-GAT, IOPcc and CRF. No association was noted between CH and spherical equivalent, keratometry, CCT, ACD, AXL, BMI or presence of diabetes or hypertension.
Keywords: cornea: clinical science • clinical (human) or epidemiologic studies: biostatistics/epidemiology methodology • comparative anatomy