XXXX affects flicker-induced vasodilation in the retina of healthy subjects.

@entity1 @entity6 @entity2479 @entity384 @entity5995 @entity4854 @entity413
Flickering light stimulation of retinal photoreceptors induces @entity384 in @entity1 . In the present study the effect of high blood @entity413 levels on this neuro-vascular mechanism was investigated in 12 healthy young male subjects. Blood @entity413 levels were consecutively increased during 30 min to 100, 200 and 300 mg/dl and kept at the respective level for the following 30 min using hyperglycemic insulin clamps. Eight Hertz flickering light was applied to the fundus at the end of each @entity413 plateau during continuous retinal vessel diameter measurements with the Zeiss retinal vessel analyser (RVA). During normoglycemia (100 mg/dl) flickering light induced a significant vasodilation of @entity5995 arteries (+2.8+/-0.4%, p<0.0001) and veins (+2.6+/-0.4%, p<0.0001). At 300 mg/dl blood @entity413 the flicker response in retinal veins was significantly decreased by 55% (p=0.015 versus 100 mg/dl). The modified RVA employed in the present study provides high sensitivity and is capable of studying flicker-induced @entity2479 . Using this technique the present study confirms that flickering light stimulation of the @entity1 retina induces vasodilation in retinal vessels in healthy subjects. In addition, our data indicate that the retinal vessel response to flickering light stimulation is significantly reduced during @entity4854 in @entity1 . The relevance of this finding for @entity6 remains to be shown.
