Ocular rigidity characterizes the relationship between pressure and volume changes in the
human eye and is expressed as a macroscopic coefficient. Outflow facility is a measure of the
resistance of the conventional outflow pathway and represents a parameter that is of interest
Difficulties in the measurement of ocular rigidity in the living human eye have limited our
knowledge on this parameter. However, ocular biomechanics have been implicated in the
pathogenesis of this disease. The aim of this study is to characterize the pressure volume
relation and quantify ocular rigidity and outflow facility in glaucomatous and normal eyes.
For this purpose, the investigators have recently developed a manometric method for the
measurement of ocular rigidity and outflow facility.