Relationship between Abnormalities in Neurophysiological Processes in Central and Peripheral Regions of the Retina and Clinical Parameters in Patients with Different Stages of Primary Open-Angle Glaucoma

Primary glaucoma is a disease causing the greatest number of vision-related problems. Accelerated death of retinal ganglion cells and their axons which comprise the optic nerve as well as their involvement in the pathological process of neuroglia which provides nutrition for the optic nerve are considered as the main components of the glaucomatous process. The latest clinical research methods such as scanning laser polarimetry and optical coherence tomography measure structural changes at different functional levels of the retina and the optic nerve. According to literature data, structural changes in progressive glaucomatous optic neuropathy occur prior to apparent functional and clinical manifestations of the disease. In optical coherence tomography of glaucomatous eyes a scan of the macula is recommended to be performed using the Fast Macular Thickness Map protocol; it allows detecting the additional information on the pathological process. However, in a significant number of patients primary open-angle glaucoma can be very difficult to diagnose, and the nature and localization of the damage to eye structure as well as visual functions in patients with glaucoma need to be clarified. Neurophysiological method ? electroretinography ? allows us to study the processes at different morphofunctional levels of the retina as well as to clarify the localization and nature of pathological changes in the above-mentioned structures and to control dynamics of changes in the structures of primary damage at various stages of the glaucomatous process. The objective of the research was to study the relationship between abnormalities in neurophysiological processes in central and peripheral regions of the retina and clinical parameters in patients with different stages of primary open-angle glaucoma. Materials and methods. Complex clinical and neurophysiological study of eyes of 186 patients (358 eyes) with primary open-angle glaucoma was performed at the Filatov Institute of Eye Diseases and Tissue Therapy of National Academy of Medical Sciences of Ukraine. The main group included 81 (51.92%) females and 75 (48.08%) males with different stages of the glaucomatous process. The average age of patients was 56.8±4.26 years. Neurophysiological method - electroretinography using a RETI-scan multifocal ERG system (Roland Consult, Wiesbaden, Germany) - was used to diagnose the pathological condition. Results. The strongest correlation was observed between neurophysiological processes occurring in neurons of the macular area ? cone of the outer photoreceptor cell layer of the retina and parameters of retinal light sensitivity as well as the visual field index. According to the obtained results in patients with pre-glaucoma there was a direct correlation between the bioelectrical activity of the macular cone and mean deviation of the differential light sensitivity of the retina (r=0.56, р=0.05); in patients with mild primary open-angle glaucoma there was an inverse correlation between the duration of latent periods of neurons in the macular area and the visual field index (r=-0.33, р=0.02); in patients with advanced primary open-angle glaucoma there was a direct correlation between the duration of latent period of macular cone and intraocular pressure (r=0.41, р=0.034). In patients with advanced primary open-angle glaucoma there was an inverse correlation between the duration of latent period of neurons of the retinal photoreceptor cell layer in the macular area and the visual field index (r=0.42, р< 0.029) as well as an inverse correlation between the parameters of the bioelectrical activity of the retinal photoreceptor cell layer in the macular area and those of the intraocular pressure (r=- 0.69, р< 0.0000024); a direct correlation between the parameters of latent period of the second-order neurons in the macular area and those of the intraocular pressure was also observed (r=0.47, р< 0.009).