Brain and Eye as Potential Targets for Ionizing Radiation Impact. Part v – Organic and Functional Changes Correlation on the Example of Certain Diseases

Abstract

The question about correlation between organic and functional changes in persons, exposed to radiation is still insufficiently studied. Dynamics of morbidity for different forms and classes of non-tumour diseases periodisation, proposed by epidemiologists, suggests the identification of three main periods: «early» (the first 6 post-Chornobyl accident years); «distant» (12–21 years) and «late» (22–30 years). However, the correspondence this periodisation to the results of epidemiological data, without taking into account the clinical features of the diseases, may contribute to the impression, that in the first period after a radiation disaster functional disorders (or autonomic regulation disorders, etc.) prevail in all cases. Meanwhile, the data from ophthalmological and neurological studies, which we aim to demonstrate in this paper, rather indicate the presence of a significant morphological basis for the development of functional disorders in early period after a radiation disaster. The objective of this work is analyse modern experimental, epidemiological and clinical data on the correlation between organic and functional changes, characteristic of radiation cerebro-ophthalmological effects – radiation cataracts, age-related macular degeneration, cerebral small vessel disease, and neurocognitive deficits. Materials and methods. The criteria for inclusion in the analytical review were peer-reviewed publications in PubMed/MEDLINE, Scopus, Web of Science, and manually selected papers; the results of our own research were also used. An additional analysis of the results of examinations conducted in 1991–2004 was performed, which included a total of 11 123 persons irradiated as the result of catastrophy at the Chornobyl NPP. Results. In the first period of radiation cataract development, which is a specific consequence of radiation exposure, morphological changes (lens opacities) are observed, which lead to a decrease in visual function only later. Analysing the correlation between organic and functional changes in the development of diseases, for which ionising radiation exposure is a significant risk factor, we observe a similar picture. For example, CSVD associated with arterial hypertension may be a manifestation of accelerated aging associated with exposure to ionising radiation. Similarly, the initial signs of age-related macular degeneration in radiation-exposed individuals are usually manifested by changes in the morphology of the retina, choroid, and pigment epithelium in the macular area, while functional disorders in the form of decreased central vision and metamorphopsia, etc., occur later. Key words: Chornobyl disaster, ionising radiation, age-related macular degeneration, cataract, morphological changes, small vessel disease, neurocognitive deficit.