Disease relevance of Retinal Artery

• Impaired retinal artery blood flow in IDDM patients before clinical manifestations of diabetic retinopathy [1].
• METHODS: Thrombus was photochemically induced in the central retinal artery by the combination of intravenous injection of photo-sensitive dye, rose bengal, and green laser irradiation focused on the artery [2].
• Color flow Doppler ultrasonography was used to demonstrate a significant and sustained reduction in the central retinal artery pulsatility index after administration of the calcium antagonist nimodipine to a patient with eclampsia [3].
• Short posterior ciliary artery, central retinal artery, and choroidal hemodynamics in brimonidine-treated primary open-angle glaucoma patients [4].
• The role of hyperhomocysteinemia and methylenetetrahydrofolate reductase (MTHFR) C677T mutation in patients with retinal artery occlusion [5].

High impact information on Retinal Artery

• Also porcine, canine, and ovine retinal tissue completely relaxed the contracted (with prostaglandin F2alpha) bovine retinal artery [6].
• We conclude that there are significant changes in oxygen tension near retinal arteries in streptozotocin-induced diabetes before any histopathological changes are evident [7].
• PURPOSE OF VIEW: We review recent developments in the clinical course and imaging modalities for Susac's syndrome, a clinical triad consisting of encephalopathy, branch retinal artery occlusions and sensorineural hearing loss [8].
• METHODS: CRAO was induced in the central retinal artery by intravenous injection of rose bengal and green laser irradiation of the artery [9].
• Treatment of acute central retinal artery occlusionwith the platelet glycoprotein IIb/IIIa receptor inhibitor tirofiban [10].

Chemical compound and disease context of Retinal Artery

• Ocular ischemic lesions consisted of anterior ischemic optic neuropathy in 17 (94.4%), central retinal artery occlusion in two (11.1%), and cilioretinal artery occlusion in two (of 11 patients with satisfactory fluorescein angiography [18.2%]) [11].
• Doppler ultrasonography of the central retinal artery in patients with diabetes and vascular disease treated with topical timolol [12].
• A 38-year-old woman with a history of systemic arterial hypertension developed a central retinal artery occlusion four hours after intranasal use of cocaine [13].
• However, when hypercapnia was superimposed upon acetazolamide, the resistance index fell in the internal carotid and central retinal arteries (each p < 0.05) [14].
• The purpose of this study was to evaluate the effect of intravenous prostaglandin E1 (PGE1) on the flow velocity of the ophthalmic artery and the central retinal artery in patients with peripheral vascular disease manifested by intermittent claudication [15].

Biological context of Retinal Artery

• Sildenafil had no effect on flicker-induced vasodilation in retinal arteries or veins [16].
• INTERVENTIONS: Baseline colour flow Doppler ultrasound assessment of the central retinal artery (CRA) and posterior ciliary artery (PCA) blood flow-velocity before intravenous infusion of 6 g of magnesium sulphate in 100 ml of 5% dextrose water over 20 min, followed by repeat Doppler measurement [17].
• Intraarterial fibrinolysis was performed in three patients with acute central retinal artery occlusion using recombinant tissue plasminogen activator as a fibrinolytic agent [18].
• To study the role of endothelin receptor subtypes in rabbit retinal arteries, endothelin-1 (ET-1)-induced vasoconstriction was analyzed using the ETA receptor antagonist BQ-123 and the ETB receptor agonist BQ-3020 [19].
• Pourcelot's ratio, an index of vascular resistance, measured in the central retinal artery was significantly reduced after topical application of 0.125% verapamil (P = .008) [20].

Anatomical context of Retinal Artery

• Placing a piece of bovine retinal tissue in the proximity of a contracted (ie, with prostaglandin F2alpha) retinal artery induced a complete relaxation of the retinal vessel, suggesting the involvement of a diffusible chemical vasorelaxant [6].
• RESULTS: After topical epinephrine, color Doppler ultrasound measurements were not significantly different compared with baseline measurements in the central retinal artery, posterior ciliary arteries, and superior ophthalmic vein [21].
• A significant difference (P = 0.0198) was found, however, when the changes in OABPm occurring in the timolol-treated eyes were compared with the changes occurring in the placebo-treated eyes, suggesting that the drug may have an effect upon ophthalmic artery pressure and retinal artery pressure that is expressed differently in each eye [22].
• Among the patients not receiving bifemelane, improvements were seen in two of six patients with central retinal artery disease, in 14 of 27 eyes with central retinal vein obstruction, and in 13 of 28 eyes with branch retinal vein obstruction [23].
• Methylene blue contracted endothelium intact retinal arteries but a spontaneous tone was not present in endothelial denuded arteries [24].

Associations of Retinal Artery with chemical compounds

• Hyperoxia promotes electroretinogram recovery after retinal artery occlusion in cats [25].
• Carbogen, a gas mixture of 95% O2 and 5% CO2, is given to patients with retinal artery obstruction in an attempt to improve retinal oxygenation [26].
• In a freshly enucleated bovine eye, the retinal arteries and veins constrict when phenylephrine is applied directly on the surface of the vessel walls [27].
• Twice-daily 20-day instillation of iganidipine (0.03%), but not of betaxolol (0.5%), significantly suppressed constriction of the retinal arteries induced by intravitreous injection of ET-1 at a dose of 2.5 or 0.5 ng in the ipsilateral eye [28].
• Second, nipradilol or timolol was instilled, and their effects on intravitreal injection of endothelin-1-induced retinal artery contraction were compared, to evaluate whether a pharmacologically active level of nipradilol penetrates the inner limiting layer by topical application [29].

Gene context of Retinal Artery

• Periodic Delta-like 4 expression in developing retinal arteries [30].
• Vasoactive intestinal and calcitonin gene-related peptides, tyrosine hydroxylase and nitrergic markers in the innervation of the rat central retinal artery [31].
• The presence of neuronal nitric oxide/NADPH-diaphorase and vasoactive intestinal peptide positive nerve fibers surrounding the posterior ciliary and central retinal arteries indicates a vasodilator effect in the rat optic nerve [31].
• Mechanism of adrenomedullin-induced relaxation in isolated canine retinal arteries [32].
• Inclusion criteria were SLV associated with thrombosis of the retinal artery; decrease in retinal blood flow (PSF: peak-systolic flow; EDF: end-diastolic flow velocity) and asymmetry between the two retinal arteries (>40%) documented by duplex scanning [33].

Analytical, diagnostic and therapeutic context of Retinal Artery

• RESULTS: The increase in plasma lactate concentration during intravenous infusion from 1.3 +/- 0.4 to 6.3 mmol/L and during dynamic exercise from 1.2 +/- 0.3 to 9.4 mmol/L decreased flicker responses in retinal arteries from 5.3% +/- 0.9% to 1.7% +/- 0.6% (P < 0.001) and from 3.6% +/- 0.6% to 2.0% +/- 0.8% (P = 0.03), respectively [34].
• The blood velocity and vessel diameter of the upper temporal retinal artery in the contralateral eye were measured using laser Doppler velocimetry with an eye-tracking system before and 1, 2, and 3 h after oral intake of 75 g glucose [35].
• The decrease in pulsatility index of the retinal artery after treatment with methyldopa was -0.17 +/- 0.22 (P < 0.0001) [36].
• RESULTS: In the present study cohort the mean retinal blood flow was 38.1 +/- 9.1 microl/min and the mean flow velocity in the central retinal artery was 6.3 +/- 1.2 cm/s. From these data we calculated a mean diameter of the central retinal artery of 163 +/- 17 microm [37].
• Hyperbaric oxygenation combined with nifedipine treatment for recent-onset retinal artery occlusion [38].

References