Patterns of development of retinal vascular pathology at remote time period after radiation exposure    
1 P. A. Fedirko, Dr. Sc. (Med.), Prof., 2 N.A. Garkava, Cand. Sc. (Med)
1 State Institution "National Research Center for Radiation Medicine of National Academy of Medical Sciences of Ukraine", Health physics and epidemiology Institute, Kyiv, Ukraine
2 State Establishment "Dnipropetrovsk Medical Academy of Health Ministry of Ukraine", Dnipro, Ukraine
E-mail: eye-rad@ukr.net
Background. Retinal vascular system is extremely sensitive to ionizing radiation exposure and requires priority medical examination. Probability of new accident environmental contamination with radioactive material is a factor that makes us draw a lesson from Chornobyl in details.
The purpose of the present study was to analyze regularities in development of retinal vascular pathology at remote time period after radiation exposure.
Material and Methods. We used results of long-term follow-up of two cohorts of participants of the liquidation of Chernobyl NPP accident consequences (Chornobyl liquidators) in 1986-1987. The first cohort included 5 195 Chornobyl liquidators, follow-up period 1992-2004; the second cohort included 2 892 Chornobyl liquidators, follow-up period 1988-2001.
Results. Retinal angiopathy was shown to be the most common eye disease in radiation exposed patients at remote time period after ionizing radiation exposure and to have specific characteristics. Angiopathy development risk depends on  age, stay-at-risk time and radiation dose; significant risk excess can occur at 4-5 years after radiation exposure. Incidence reached its maximum at 9 years after radiation exposure, followed by a slight incidence decrease with a re-increase in next 4 years.
Conclusion. Pathology of retinal vessels is the most common eye disease in radiation exposed persons and can develop as early as 4-5 years after radiation exposure. The main risk factors for its development are age and  external radiation dose. Primary angiopathy incidence reached the first maximum at 9 years with re-increase at 13 years after radiation exposure.
Key words: retinal vascular pathology, radiation exposure    
1.    [Chornobyl 20 years later. A look at the future: National Report of Ukraine]. Kyiv: Atika; 2006. 232 p. Ukrainian.
2.    Fedirko PA, Garkava NA, Krynnychna IP. [Remote effects of ionizing radiation exposure.] Proceedings of International Scientific Practical Conference. Kyiv 23-25 May 2007. K.; 2007: 148-149. Ukrainian.
3.    Koteluanskaya KE, Obukhovskiy GA. Angiopathy of the visual organ in inhabitants of radiation contaminated areas of the Rovno region. Oftalmol Zh. 2000;5:43-5. Russian.  
4.    Hmidan Nabil, Piskovatsky P, Soldatova AM. Violations of eye hemodynamics and cardiac hemodynamics in liquidators of the Chernobyl consequences and possible ways of their correction. Oftalmol Zh. 1997;4:259-64. Russian.  
5.    Buzunov V, Fedirko P. Ophthalmopathology in victims of the Chornobyl catastrophy – results of clinical epidemiological study. In: Ocular radiation risk assessment in populations exposed to environmental radiation contamination. Junk AK, Kundiev Y, Vitte P, Worgul BV (ed). KluwerAc. Publish:  Dordrecht /Boston / London; 1999. 57–67.