Hemma Resch

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PURPOSE Various studies have shown that retinal vessels in patients with diabetes mellitus have a reduced capacity to adapt to changes in perfusion pressure and to stimulation with flickering light. Structural and functional changes in retinal vessels in diabetes could lead to a general reduction of vasodilator and/or vasoconstrictor capacity. To gain more(More)
PURPOSE There is evidence from theoretical models and animal studies that the biomechanical properties of the optic nerve head and the sclera play a role in the pathophysiology of glaucoma. There are, however, only a few data available that demonstrate such biomechanical alterations in vivo. In this study, the hypothesis was that patients with primary(More)
PURPOSE Several lines of evidence indicate that altered blood flow regulation may contribute to the pathogenesis of glaucomatous optic neuropathy. Recent data support the hypothesis that the endothelin system is involved in the processes that lead to vascular dysregulation in glaucoma. This study was conducted to test the hypothesis that bosentan, a dual(More)
PURPOSE It has been shown that stimulation with diffuse luminance flicker induces vasodilatation in the human retina and increases optic nerve head (ONH) blood flow. The present study was designed to investigate the influence of a short-term increase in intraocular pressure on flicker-induced changes in ONH blood flow and retinal vessel diameters. METHODS(More)
PURPOSE It has been hypothesized that carbon monoxide (CO) acts as an important vascular paracrine factor and plays a role in blood flow regulation in several tissues. The present study investigated the effect of inhaled CO on retinal and choroidal blood flow. METHODS Fifteen healthy male volunteers were studied in a randomized, double-masked,(More)
PURPOSE Animal studies suggest that retinal and choroidal blood flow decrease after administration of indomethacin, a nonspecific cyclooxygenase inhibitor. Cyclooxygenase is the key enzyme involved in the arachidonic pathway and regulates the production of vasoactive substances such as prostaglandins and thromboxans. The aim of the present study was to(More)
PURPOSE Little is known about potential effects of smoking on ocular blood flow regulation. In the present study, the hypothesis was that choroidal blood flow (CBF) changes during an increase in ocular perfusion pressure induced by isometric exercise are altered in chronic smokers. METHODS The study was performed in 24 (12 smokers and 12 nonsmokers)(More)
PURPOSE To determine the effect of intravenously administered histamine on both retinal and choroidal blood flow in humans. METHODS A randomized, double-masked, two-way crossover study was performed in 14 healthy volunteers. Placebo or histamine was administered intravenously in stepwise increasing doses (0.08 microg/kg/min, 0.16 microg/kg/min, and 0.32(More)
PURPOSE The present study tested the hypothesis that human choroidal blood flow (ChBF) regulation in the face of changes in ocular perfusion pressure (OPP) may be modified by a drug-induced decrease in intraocular pressure (IOP). METHODS This hypothesis was tested in a double-masked, randomized, placebo-controlled, parallel-group trial in 24 healthy(More)
AIM To evaluate the correlation of the retinal blood vessel position and the retinal nerve fibre layer (RNFL) thickness profile. METHODS RNFL thickness of 81 healthy subjects was measured using scanning laser polarimetry (SLP). To quantify the retinal blood vessel position, the angle (superior and inferior) between a horizontal line and a line from the(More)