Acta ophthalmologica
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Acta ophthalmologica · Feb 2009
Colour Doppler imaging evaluation of blood flow parameters in the ophthalmic artery in acute and chronic phases of optic neuritis in multiple sclerosis.
Optic neuritis (ON) is a common manifestation of multiple sclerosis (MS). It is caused by the immune-mediated inflammation of the optic nerve. Some vascular factors that may influence blood flow in the ophthalmic artery (OA) have also been suggested as factors in the pathogenesis of ON. The purpose of our study was to evaluate blood flow velocities and resistance (RI) and pulsatile (PI) indices in the OA in both orbits in patients in the acute and chronic phases of unilateral ON and to compare these with equivalent findings in healthy control subjects. ⋯ Pathophysiological changes during acute unilateral ON influence orbital haemodynamics, as is indicated by increased PSV, RI and PI in the OA in eyes affected with ON. However, these changes do not persist over longer periods.
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Acta ophthalmologica · May 2008
Safety, penetration and efficacy of topically applied bevacizumab: evaluation of eyedrops in corneal neovascularization after chemical burn.
That vascular endothelial growth factor (VEGF) plays a major role in inflammatory angiogenesis has been well established. This pilot study was designed to evaluate experimental treatment with bevacizumab eyedrops in corneal neovascularization induced by alkali burn. The feasibility of topical administration, corneal cell viability and corneal penetration were investigated in an animal model. ⋯ The data from this pilot study suggest that bevacizumab eyedrops can sufficiently penetrate the corneal stroma and anterior chamber. When administered soon after alkali burn, bevacizumab seems to significantly reduce corneal damage. Combinations of established treatment regimens with topical bevacizumab might be considered in severe injuries with otherwise devastating prognoses.
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Acta ophthalmologica · Feb 2008
The relaxing effect of perivascular tissue on porcine retinal arterioles in vitro is mimicked by N-methyl-D-aspartate and is blocked by prostaglandin synthesis inhibition.
Retinal hyperperfusion resulting from disturbances in the regulation of arteriolar tone is involved in the pathophysiology of a variety of retinal diseases. The mechanisms underlying this regulation of tone involve cellular components in both the vascular wall and the perivascular tissue. However, previous in vitro studies of the influence of perivascular retinal tissue on retinal tone regulation have been hampered by the release of an endogenous relaxing factor that renders the arteriole insensitive to vasoconstrictors. The purpose of the present study was to test whether N-methyl-D-aspartate (NMDA) and gamma-amino butyric acid (GABA) receptors, and a cyclooxygenase (COX) product influence this effect of perivascular retinal tissue in vitro. ⋯ The inhibition of vascular contractility induced by perivascular retinal tissue in vitro involves NMDA-receptors and an effect of GABA-mimetic substance on retinal tissue. The generation of these effects involves a COX product.