Petersen L, et al. - Researchers analyzed 7 candidates to describe the diameter variations of retinal vessels to understand the pathophysiology of the Coats' disease. They observed a larger baseline diameter of retinal vessels in the affected eyes when compared to the unaffected eyes, significantly for the arterioles. They noted the absence of normal contraction of arterioles in both eyes during an increase in the arterial blood pressure induced by isometric exercise and a significant dilatation of the venules in the unaffected eyes. They found the induction of normal dilatation of retinal vessels in both affected and unaffected eyes due to stimulation with flickering light.