Investigative ophthalmology & visual science
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Invest. Ophthalmol. Vis. Sci. · Mar 2006
Randomized Controlled TrialIntravenous administration of diphenhydramine reduces histamine-induced vasodilator effects in the retina and choroid.
Intravenous administration of histamine causes an increase in choroidal blood flow (ChBF) and retinal vessel diameters in healthy subjects. The receptor mediating this response has not yet been identified. The present study was undertaken to clarify whether H1 receptor blockade with diphenhydramine affects the hemodynamic response of histamine in the choroid and the retina. ⋯ The present data confirm that histamine increases ChBF and retinal vessel diameters in healthy subjects. Administration of the H1 receptor blocker diphenhydramine significantly reduced histamine-induced changes in ocular perfusion parameters. These results strongly indicate that in the retina and choroid, H1 receptors are involved in the histamine-mediated hemodynamic effects in vivo.
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Invest. Ophthalmol. Vis. Sci. · Dec 2005
Randomized Controlled TrialSystemic omega-6 essential fatty acid treatment and pge1 tear content in Sjögren's syndrome patients.
To determine the effect of oral omega-6 essential fatty acids on PGE(1) tear content and signs and symptoms of ocular discomfort in patients with Sjögren's syndrome (SS). ⋯ Omega-6 administration increases the PGE1 levels in tears of patients with SS and improves ocular surface signs and symptoms of ocular discomfort.
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Invest. Ophthalmol. Vis. Sci. · Nov 2003
Randomized Controlled Trial Clinical TrialEffects of sildenafil on retinal blood flow and flicker-induced retinal vasodilatation in healthy subjects.
Sildenafil is a specific inhibitor of phosphodiesterase V, which is widely used for the treatment of erectile dysfunction. Sildenafil has been shown to induce vasodilation in several vascular beds by inhibiting the cGMP breakdown. The present study was conducted to investigate whether sildenafil increases blood flow in the human retina. ⋯ The data indicate that sildenafil increases retinal venous diameters and retinal blood flow in healthy subjects. By contrast, it does not affect intraocular pressure and flicker-induced retinal vasodilation. Further studies are needed to elucidate whether this drug may be therapeutically used in retinal ischemic disease.
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Invest. Ophthalmol. Vis. Sci. · Sep 2003
Randomized Controlled Trial Clinical TrialEffect of intravenous administration of sodium-lactate on retinal blood flow in healthy subjects.
The present study was designed to investigate the effect of intravenously administered sodium lactate on ocular blood flow. ⋯ The data indicate that intravenously administered sodium lactate increases retinal blood flow. Whether this is related to a cytosolic redox impairment or to other hitherto unidentified mechanism remains to be clarified. Further studies are needed to determine whether lactate plays a role in regulation of choroidal blood flow.
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Invest. Ophthalmol. Vis. Sci. · Aug 2003
Randomized Controlled Trial Clinical TrialScotopic electroretinogram in term infants born of mothers supplemented with docosahexaenoic acid during pregnancy.
To test the hypothesis that the supplementation of the diets of pregnant women with a fish oil rich in docosahexaenoic acid (DHA) enhances retinal development in their healthy term infants, as measured during the early postnatal period by the electroretinogram (ERG). ⋯ These findings demonstrate an association between the DHA status of term infants and retinal sensitivity, suggesting an essential role of this long-chain polyunsaturated fatty acid (LCPUFA) in the development and function of the retina. However, maternal DHA status was not significantly associated with infant retinal sensitivity and no direct effect of maternal supplementation was observed.