BRAIN AND EYE AS POTENTIAL TARGETS FOR IONIZING RADIATION IMPACT. PART III - FEATURES MORPHOMETRIC RETINAL PARAMETERS, AMPLITUDE AND LATENCY COMPONENTS OF VISUAL EVOKED POTENTIAL IN RADIATION EXPOSED IN UTERO

Abstract

One of the current problems of modern radiobiology is determine the characteristics of the manifestation of radiation-induced effects not only at different dose loads, but also at different stages of development of the organism. In previous reports, we have summarized available evidence that at certain ages there is a comparative acceleration of radiation-induced pathological changes in the eye and brain, and the study and assessment of the risk of possible ophthalmic and neurological pathology in remote periods after contamination of radioactive areas. Data of irradiated in utero individuals are possible on the basis of observation of the state of the visual analyzer in persons who underwent intrauterine irradiation in 1986. Therefore, a parallel study of retinal morphometric parameters, amplitude and latency of components of evoked visual potentials in irradiated in utero individuals was performed. Objective: to evaluate the retinal morphometric parameters, amplitude and latency components of the evoked visual potentials in intrauterine irradiated persons. Materials and methods. The results of surveys of 16 people irradiated in utero in the aftermath of the Chornobyl disaster were used; the comparison group were residents of Kyiv of the corresponding age (25 people). Optical coherence tomography was performed on a Cirrus HD-OCT, Macular Cube 512x128 study technique was used. At the same time, the study of visual evoked potentials on the inverted pattern was performed, and occipital leads were analyzed. Visual evoked potentials were recorded on a reversible chess pattern (VEP) – an electrophysiological test, which is a visual response to a sharp change in image contrast when presenting a reversible image of a chessboard. Results. In those irradiated in utero at the age of 22–25 years, there was a probable increase in retinal thickness in the fovea, there was a tendency to increase the thickness of the retina in the areas around the fovea. When recording visual evoked potentials on a reversible chess pattern in this group, there was a tendency to decrease the amplitudes of components (N75, P100, N145, P200) in the right and left parieto-occipital areas and asymmetric changes in latency of these components. Conclusions. Early changes of fovea recorded in OCT and decreasing amplitudes of components of visual evoked potentials on the reversible chess pattern at the age of 22–25 years may indicate a risk of development in patients irradiated in utero, early age-related macular degeneration, as well as increased risk and increased risk structures of the visual analyzer. Key words: induced visual potentials, optical coherence tomography, retina, agerelated macular degeneration, ion izing radiation, dose.