Ressortforschungsberichte zur kerntechnischen Sicherheit und zum ...

- Investigation of confounders for the development of cataracts by relevant questioning.
Minimisation of information bias.
6.2 Results of work package 2
Work package 2 gives an overview of all collectives that can be considered for an epidemi-
ological study on the relationship between exposition with ionizing radiation and the devel-
opment of cataracts in Germany. Radiation exposed occupational and patient groups as well
as population-based cohorts were checked for their suitability for an epidemiological study
according to the quality criteria mentioned in work package 1. Methodological aspects as
well as feasibility aspects were taken into consideration. Several collectives were identified,
which are suitable in principle for an epidemiological study.
Among the occupational collectives, the groups of interventional cardiologists and radiolo-
gists, as well as of flight crews are those with the highest success chance for gaining sub-
stantial results on the dose-dependancy between low dose ionising radiation and cataract
development from an epidemiological study. The two collectives are large and quite ho-
mogenous. They belong to the job groups with the highest exposure. A good dosimetry as
well as a good, prospective cataract diagnosis can be achieved in both cases. In both collec-
tives a high participation rate can be expected among the study subjects of both collectives.
Regarding the occupational group of nuclear power workers, the experience of the authors
from a study on cancer among this population shows that the recruitment of such a cohort in
Germany might be difficult.
Other groups registered in the radiation protection register are heterogeneous and scattered
which would lead to a high logistical complexity. Patient collectives are heterogeneous, and
the number of patients per clinic exposed to radiation in the head or neck is too small to
perform a study. A further large study collective, which could potentially be a basis for a
case-control study, are people with cataract, but occupational or medical radiation expo-
sures in this collective are rare. However, a collective like this is easy to recruit due to their
presence on the spot and is therefore suitable to optimize e.g. the questionnaire and eye
examination. Population-based cohort studies contain few patients exposed to radiation that
goes beyond short diagnostic radiography, and former studies hardly ever included cataract
examination. In the Gutenberg Heart Study performed at the University Medical Center
Mainz a cataract examination is carried out, but the examinations are not done with a
dilated pupil, which would be necessary for the planned study.
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