Die Abhängigkeit der arteriellen und venösen retinalen Gefäßverschlüsse von der Jahreszeit und dem Wetter
In this study the seasonal and meteorological influence on the incidence of 173 retinal arterial and 275 retinal vein occlusions was examined retrospectively over a five-year period. In the first part of this study the incidence of the retinal vein occlusion showed a significant cyclic variation, being most frequent in the months of October and November and rarest in February. The four-seasonal variation with a minimum in summer and a maximum in autumn was also significant. The incidence of the retinal arterial occlusions showed no monthly cyclic variation, but distribution to the four seasons showed a significant minimum in spring and a significant maximum in winter. The significant cyclic variations in the onset of retinal occlusions suggest that exogenous seasonal factors may be important in the pathogenesis in addition to the well-known association with endogenous diseases. Seasonal variations are surely not the cause of retinal occlusions but may be the seasonal influence acts as a trigger on patients with risk factors. The organism shows through the means and the power of reactions its ability of adaptation and its capabilities ; i.e. where its “locus minoris resistentiae” is. The winter peak of retinal arterial occlusions and the accumulation of retinal vein occlusions in the winter indicate the influence of temperature. Coldness stimulus causes changes of rheological parameters and influences blood pressure and blood flow as well as the sympathicus tonus. These changes can have negative effects on risk patients. But the coldness stimulus does not explain the early peak of retinal vein occlusions in autumn. There must be an influence of other seasonal factors. In general the adaptation to the change of weather or other seasonal factors may be a burden for risk patients with low adaptability. These changes act as a stressor. Stress leads to an increase of the sympathicus tonus and therefore to changes in rheological parameters, blood pressure and blood flow. In the second part of this study the correlation between the incidence of retinal vein and arterial occlusions and the daily weather situation, the dynamic of atmosphere changes, which is divided into 13 biotropical grades, was examined. The result showed neither for retinal arterial nor for retinal vein occlusions a significant high incidence to certain weather situations, especially not to so-called “trouble-weather”, e.g. the passing of a cold or a warm front. Because no influence of meteorological factors could be shown, it seems necessary to discuss further factors likeinfection rates in winter, the seasonal variation of intraocular pressure and changes of lifestyle and eating habits in order to explain the seasonal divergences.
info:eu-repo/classification/ddc/610, Medizin
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