THEORETICAL JUSTIFICATION OF A NEW METHOD IN CILIARY BODY MICROCIRCULATORY ISCHEMIA DIAGNOSTICS

PURPOSE: A theoretical justification of a new method of diagnosing the ciliary body microcirculatory ischemia.

METHODS: Mathematical modeling of high-frequency current distribution in eye tissues during electrical impedance plethysmography (IPG). Mathematical modeling of converting the degree of local short-term globe vacuum compression into the level of intraocular pressure (IOP) elevation.

RESULTS: The possibility to diagnose the ciliary body microcirculatory ischemia has been theoretically substantiated. According to the utility model, original suction ring with rheographic electrodes was applied to perilimbal sclera. Diastolic ocular perfusion pressure (OPP) was determined by means of ocular impedance plethysmography (IPG) in arterioles of the ciliary body microcirculation bed, excluding the contribution of blood circulation in superficial subconjunctival vessels of the anterior eye segment and in intraocular vessels of the posterior eye segment. Determination of perfusion pressure in small vessels of the anterior eye segment was carried out at a lower IOP level. Aqueous humor inflow and outflow was temporarily blocked during the examination to ensure an unchanging eye globe volume. The following formula was used to calculate OPP: , where VAC is the degree of vacuum compression applied and D is the eye globe diameter, coefficient K is determined by specific dimensions of suction ring. The ciliary body microcirculatory ischemia was diagnosed when diastolic OPP was below 35.0 mmHg.

CONCLUSION: The proposed method of determining diastolic OPP in the arterioles of the ciliary body microcirculation bed in case of experimental confirmation could be useful for early detection of intraocular vascular microcirculation disorders not only in patients with glaucoma (including low pressure glaucoma), but also in cases of myopia, diabetic angiopathy, peripheral retinal degeneration, age-related macular degeneration, uveitis, and it could also allow the assessment of the treatment effectiveness after conservative therapy and surgical interventions.

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