Abstract
Purpose:
Evidence has accumulated that the biomechanical properties of the optic nerve head and the sclera play a role in the pathophysiology of glaucoma. In this study, the hypothesis was tested that abnormal ocular structural stiffness as estimated based on measurements of intraocular pressure amplitude and ocular fundus pulsation amplitude is dependent on intraocular pressure.
Methods:
Onehundredsixtyeight healthy subjects aged between 18 and 45 years were included in this study. The ocular pulse amplitude and pulsatile ocular blood flow were assessed with pneumotonometry. The fundus pulsation amplitude was measured by using laser interferometry. Based on the Friedenwald equation, a coefficient of ocular rigidity (E1) was calculated relating pulse amplitude to fundus pulsation amplitude
Results:
The ocular fundus pulsation amplitude was 4.21 ± 0.99 μm, the ocular pulse amplitude was 3.07 ± 0.61 mmHg. This resulted in a calculated factor E1 of 0.047 ± 0.007 AU. Multiple regression analysis revealed that fundus pulsation amplitude and pulse amplitude were dependent on pulse pressure amplitude (p < 0.001) whereas E1 was dependent on intraocular pressure (p < 0.001).
Conclusions:
The present study indicates that ocular rigidity is dependent on intraocular pressure.
Keywords: 568 intraocular pressure