[Role of active and passive modulations of ocular microcirculation in altering the morphometric parameters of the optic disk in primary glaucoma].

The authors studied the influence of active and passive modulations of ocular microcirculation on the morphometric parameters of the head of the optic nerve and their correlation in patients with primary open-angle glaucoma in the presence of elevated and normalized intraocular pressures (IOP). Ocular microcirculation was examined by the contact method on a LAKK-01 Doppler laser flowmeter. The morphometric parameters were explored by scanning laser ophthalmoscopy on a NRT device. Analysis showed a significant linear correlation of the active and passive modulations of microcirculation with the thickness of a retinal nerve fiber layer, the area and volume of the neuroretinal rim, and the volume profile of excavation in both types of microcirculatory changes. On the bases of the derived ratios, it has been concluded that in patients with the hyperemic type of microcirculation, active modulation mechanisms (enhanced neurogenic and myogenic activities of afferent microvessels) are responsive for glaucomatous optic neuropath in the presence of elevated IOP. In patients with the spastic type, decreased neurogenic and myogenic activities of afferent microvessels are an independent mechanism of tissue damage in the head of the optic nerve in normalized IOP.