ЗНАЧЕННЯ ІНДЕКСУ ВИТРИВАЛОСТІ ДЛЯ ДІАГНОСТИКИ ФУНКЦІОНАЛЬНОГО СТАНУ КОНВЕРГЕНТНО-АКОМОДАЦІЙНОГО АПАРАТУ ОРГАНУ ЗОРУ

Abstract. Relevance of the study. Current medical methods for the treatment of myopia do not guarantee long-term stability of the achieved results. The inclusion of physical therapy methods in treatment and prevention programs for myopia is pathogenetically justified; however, the development of new rehabilitation approaches requires innovative methodological solutions. In this context, a concept of integrating physical therapy methods into comprehensive treatment and prevention of myopia is substantiated based on the morphofunctional organization of the visual sensory system. One of its key components is the oculomotor system, which characterizes the functional state of the convergence-accommodation apparatus of the eye. To assess the functional state of this component, we previously developed methods for evaluating the endurance and endurance index of the convergence–accommodation apparatus. Purpose of the study is to establish the value of the endurance index for diagnosing the functional state of the convergent-accommodative apparatus of the organ of vision. Material and methods. Using the developed method for assessing the endurance of the convergence–accommodation apparatus, the endurance index was determined prior to visual load during near-vision tasks (viewing distance of 33 cm) involving fonts of different sizes from a standard visual acuity chart. The study sample included 30 participants – students aged 18-19 years with low-degree myopia and individuals with normal refraction. The procedure involved the sequential presentation of two fonts to each participant: first corresponding to visual acuity of 0.6, followed by a font corresponding to visual acuity of 1.0. The accommodative moment was recorded as the time (in seconds) from the onset of stimulus presentation to the moment of clear visual perception and served as the primary parameter for further analysis. Results and key conclusions. The duration of the accommodative moment can serve as a physiological basis for developing a method to assess the working capacity of the oculomotor component of the functional visual sensory system. The endurance indicator of the convergence-accommodation apparatus, calculated based on the difference in accommodative moment duration under conditions of exposure to fonts of different sizes (No. 6 and No. 1), indirectly reflects the functional level of the muscular component of the visual system. The endurance index of the convergence-accommodation apparatus is an indicative variable that qualitatively characterizes the functional reserve of the muscular component of the visual apparatus. The study revealed differences in the functional state of the muscular component of the visual system in individuals with established myopia compared to those with normal refraction, confirming the diagnostic informativeness of the proposed method. Measurement of the endurance indicator and its index prior to visual load may be used to evaluate the effectiveness of prescribed physical therapy programs in the treatment and prevention of myopia.