The Effect of Corneal Biomechanical Factors on Ocular Pulse Amplitude in Normal Subjects

ABSTRACT

PURPOSE: To investigate the influence of corneal biomechanical factors on ocular pulse amplitude measured using dynamic contour tonometry in normal subjects. METHODS: The study population consisted of normal subjects who visited the outpatient clinic from January, 2014 to July, 2014. Ocular pulse amplitude was measured using dynamic contour tonometry and corneal hysteresis (CH) and corneal resistance factor (CRF) were measured using an ocular response analyzer. We applied univariate and multivariate linear regressions to investigate the relationship between ocular pulse amplitude and corneal biomechanical factors and other ocular factors. RESULTS: Fifty eyes of 50 patients (average age 52.8 +/- 17.2 years) were examined. The average ocular pulse amplitude was 2.90 +/- 1.04 mm Hg and the CH and CRF were 10.44 +/- 1.96 mm Hg and 11.03 +/- 2.21 mm Hg, respectively. In univariate linear regression, factors influencing ocular pulse amplitude were ocular pressure based on CRF (beta = 0.280, p = 0.049), Goldmann applanation tonometry (beta = 0.293, p = 0.039), and spherical equivalent (beta = 0.283, p = 0.047), while in multivariate linear regression the only factor influencing ocular pulse amplitude was CRF (beta = 0.686, p = 0.042). CONCLUSIONS: A positive correlation between ocular pulse amplitude reflecting ocular perfusion pressure and CRF reflecting corneal elasticity was observed. Correlations between the 2 factors will be an important aspect in future studies regarding the influences of corneal biomechanical factors on ocular perfusion pressure in glaucoma patients.