ABSTRACT
Changes in the hemodynamic parameters of the eye were examined in patients with primary open-angle glaucoma (OAG) in the well developed and far advanced stages with moderately increased (up to 32 mm Hg) and high (33 mm Hg and higher) pressure before and after surgery. Computer-aided vacuum ophthalmodynamometer was used with a sucking cup calibrated for two levels of ophthalmic tone, whose external diameter was 13 mm and funnel angle 60 degrees. A total of 59 patients (82 eyes) aged 50 to 84 years were examined, control group consisted of 18 patients (36 eyes). Mean dynamic pressure in the orbital artery and perfusion pressure were measured, and the orbital-brachial coefficient estimated. Progressive decrease of perfusion pressure was paralleled by increase of the mean dynamic pressure in the orbital artery in patients with stages Iic and IIIb OAG and by its decrease in those with stage IIIc OAG. Such changes of the hemodynamics are explained by the compensatory work of the ocular bloodflow autoregulation mechanism in the first case and its failure in the second. After regression analysis, linear equations of the relationship between changes in the mean dynamic pressure and intraocular pressure were calculated. After surgery, changes in the hemodynamic parameters were followed up for 12 months in 27 eyes with well-developed condition and for 6 months in 13 eyes with far advanced condition.
