Abnormalities of retinal vasculatures can indicate health conditions in the body, such as the high blood pressure and diabetes. Providing automatically determined width ratio of arteries and veins (A/V ratio) on retinal fundus images may help physicians in the diagnosis of hypertensive retinopathy, which may cause blindness. The purpose of this study was to detect major retinal vessels and clas...

Segmentation of blood vessels in retinal images is an important part in retinal image analysis for diagnosis and treatment of eye diseases for large screening systems. In this paper, we addressed the problem of background and noise extraction from retinal images. Blood vessels usually have central light reflex and poor local contrast, hence the results yield by blood vessel segmentation algorit...

The appearance of retinal blood vessels is an important diagnostic indicator of serious disease, such as hypertension, diabetes, cardiovascular disease, and stroke. Automatic segmentation of the retinal vasculature is a primary step towards automatic assessment of the retinal blood vessel features. This paper presents an automated method for the enhancement and segmentation of blood vessels in ...

PURPOSE Antiangiogenic treatment is a promising new therapy for angiogenesis-dependent diseases. In the current study, the biologic effects on pathologic and physiological angiogenesis in the retina of angiostatin, a very potent angiogenesis inhibitor were determined. In addition, the effects of angiostatin on the growth and development of newborn mice were examined. METHODS Oxygen-induced re...

Ocular fundus image can provide information on pathological changes caused by local ocular diseases and early signs of certain systemic diseases. Automated analysis and interpretation of fundus images has become a necessary and important diagnostic procedure in ophthalmology. Among the features in ocular fundus image are the optic disc, fovea (central vision area), lesions, and retinal vessels....

To consider whether imaging retinal vasculature may be used as a marker for cortical vessels, we compared fluorescein angiography flow dynamics before and after pharmacological disruption of blood-neural barriers. Sodium fluorescein (1%, 200 μl/kg) was intravenously delivered in anesthetized adult Long Evans rats (n = 44, brain = 18, retina = 26). In the brain cohort, a cranial window was creat...

The retinal blood vessels serve for nutrition of the retinal ganglion cells and their axons. This study was undertaken to evaluate the vessel diameter in normal and glaucoma eyes. The calibers of the superior temporal and inferior temporal retinal artery and vein were measured at the optic disc border and at a distance of 2 mm from the optic disc center; 473 eyes of 281 patients suffering from ...

In hypertension and diabetes retinal vascular changes which are evident on fundiscopic examination are usually accompanied by renal vascular changes which are evident on microscopic examination. It has been found that the retinal vessels of most patients with hypertension or diabetes fail to constrict normally when the blood oxygen tension is elevated. This investigation evaluates the clinical ...

PURPOSE Recent studies suggest that the cannulation of retinal vessels may provide a potential access route for the administration of thrombolytic agents in retinal vessel occlusion. However, the major problem with available techniques is the limited visualization of retinal vessels with conventional surgical microscopes, making it difficult to effectively control the targeted injection of drug...

THE eye is the only part of the body in which blood vessels can readily be observed. In disease, retinal blood vessels may show pathological variations in calibre, the severity of which at times reflects the progress of the disease, whether local as in retinitis pigmentosa, or systemic as in spastic hypertension. Spasticity of retinal vessels may show measurable alteration after treatment, in p...