Lack of correlation between short-term dynamics of diabetic retinopathy lesions and the arterial blood pressure.

INTRODUCTION: Diabetic retinopathy is characterized by morphological lesions in the ocular fundus related to impairment of the retinal blood flow. The morphological lesions display a dynamic pattern of new formation and resorption of lesions, with a turn-over within days to weeks that may reflect basic pathophysiological mechanisms underlying the disease. However, a possible relationship between short-term fluctuations in diabetic retinopathy and risk factors for the long-term prognosis of diabetic retinopathy, such as the arterial blood pressure, has not been investigated.
METHODS: Five patients with moderate non-proliferative diabetic retinopathy were examined by fundus photography and measurement of the blood pressure at 1- to 2-week intervals for up to 1 year. The numbers of microaneurysms/haemorrhages and hard exudates in the macular area were counted, and changes in these counts were related to changes in the arterial blood pressure.
RESULTS: The five patients discontinued the study after 1-12 months, which resulted in between 5 and 39 examinations per patient, and amounted to a total of 101 examinations. There was a significant covariation between microaneurysms/haemorrhages and hard exudates, whereas there was no significant covariation between the number of either type of lesion and the blood pressure.
CONCLUSIONS: The cause of dynamic changes in diabetic retinopathy lesions occurring over days to weeks may involve other factors than changes in the arterial blood pressure.