BACKGROUND It has been proposed that sildenafil citrate can increase ocular blood flow, and that this property can be used to treat ocular disorders that involve reflex vasoconstriction. This study therefore proposes to ascertain the vasodilator effect of the drug on retrobulbar circulation in healthy rabbits. For this matter rabbits treated with sildenafil citrate or saline solution had their ...

AIM/BACKGROUND In diabetic eye disease the factors leading to compromised circulation and the resulting loss of visual function are poorly understood. Although retinal circulation has been widely investigated, it accounts for only a fraction of total eye blood flow. Blood flow was investigated in the larger vessels feeding the eye in patients with early diabetic retinopathy. METHODS Eleven pa...

Endocannabinoids regulate vascular tone in a variety of vascular tissues. This study aimed to investigate the role of peroxisome proliferators-activated receptors (PPARs) in anandamide- and palmitoylethanolamide-induced relaxant responses on the bovine ophthalmic artery and to evaluate the mechanisms involved. The effects of anandamide and palmitoylethanolamide were examined under myographic co...

OBJECTIVE To study the effects of segmental scleral buckling without encircling procedures on retrobulbar hemodynamic conditions using color Doppler imaging. METHODS In 65 consecutive eyes of 65 patients with unilateral rhegmatogenous retinal detachment repaired by scleral buckling, we prospectively measured the blood flow velocities in the ophthalmic artery, central retinal artery, and short...

The pressure-induced constriction in the rat ophthalmic artery was characterized. Ophthalmic arteries were isolated, cannulated in an arteriograph, and pressurized. Arteries developed 25% constriction at 70 mmHg of intraluminal pressure. Arteries maintained almost similar diameter over the range of pressures 50-210 mmHg, and forced dilatation was observed at pressures >210 mmHg. Denudation of e...

Cholinergic regulation of arterial luminal diameter involves intricate network of intercellular communication between the endothelial and smooth muscle cells that is highly dependent on the molecular mediators released by the endothelium. Albeit the well-recognized contribution of nitric oxide (NO) towards vasodilation, the identity of compensatory mechanisms that maintain vasomotor tone when N...

PURPOSE To determine whether retrobulbar blood flow (RBF) velocities are predictive of conversion to glaucoma. METHODS A total of 262 glaucoma suspects were prospectively selected. Participants had normal visual field, increased intraocular pressure, and glaucomatous optic disc appearance at baseline. Topographic analysis of the optic nerve head was performed using a confocal laser scanning o...

BACKGROUND Ophthalmic artery chemosurgery (OAC) for retinoblastoma was introduced by us 5 years ago for advanced intraocular retinoblastoma. Because the success was higher than with existing alternatives and systemic side effects limited we have now treated less advanced intraocular retinoblastoma (Reese-Ellsworth (RE) I-III and International Classification Retinoblastoma (ICRB) B and C). MET...

The arterial blood supply to the eye is provided by the ophthalmic artery, one of the branches of the internal carotid artery. The branches of the ophthalmic artery which meet the metabolic needs of the globe are central retinal artery, short and long posterior ciliaries, anterior ciliaries. The central retinal artery enters the globe through the optic nerve and supplies blood to the inner laye...