On the possibility to use parameters that characterize the elastic properties of the corneoscleral coat of the eye for the diagnostics of its abnormal mechanical state at primary open-angle glaucoma

The possibility to use in ophthalmology practice certain tonometry-based characteristics of the elastic properties of the corneoscleral coat at primary open-angle glaucoma is justified by mathematical modelling. As a theoretical basis for modelling, the model of the eyeball the authors developed earlier is used. The proposed mechanical criteria, which correlate with the severity of the disease, are verified using the Maklakoff and Schiøtz tonometers. The results testify in favor of the contemporary hypothesis about the correlation between the primary open-angle glaucoma severity and the level of abnormality of the elastic properties of the corneoscleral coat of the eye. It is shown that the progress of the disease is accompanied by increase in the Schiøtz pressure difference coefficient and decrease in the similar Maklakoff coefficient. An important additional information is given by the ratio of these coefficients. As follows from calculations, such changes correspond to increase in scleral stiffness simultaneously with a more significant increase in the stiffness of the cornea.