This paper presents an analysis of the bifurcations of retinal vessels. The angles and relative diameters of blood vessels in 230 bifurcations were measured using a new automated procedure, and used to calculate the values of several features with known theoretical properties. The measurements are compared with predictions from theoretical models, and with manual measurements. The automated mea...

BACKGROUND AND OBJECTIVE Vitrectomy markedly alters the intraocular milieu, which can then affect the physiology of the retina and choroid. This study investigates whether vitrectomy also alters ocular blood flow as determined by laser speckle flowgraphy (LSFG). PATIENTS AND METHODS Twenty eyes of 20 patients that underwent vitrectomy for idiopathic macular hole or epiretinal membrane were st...

Retinal vascular region is recognized as the promising anatomical for diagnosis of several commonly seen diseases including cardiovascular related and diabetes. In this paper we propose two novel deep neural architectures named Dilated fully convolved convolutional network (FCNN) dilated depth concatenated (DCNN) to segment retinal blood vessels. The proposed work evaluated both with without di...

PURPOSE To investigate the impact of cataract surgery and blood pressure changes induced by one week of sodium restriction on retinal vascular diameter. METHODS Fundus photographs of 200 patients were obtained before and one week after cataract surgery. For one week after admission, 100 patients received sodium restriction and 100 patients (ie, the control group) did not receive sodium restri...

This paper proposes a biometric system for authentication that uses the retina blood vessel pattern. The retina biometric analyzes the layer of blood vessels located at the back of the eye. The blood vessels at the back of the eye have a unique pattern, from eye to eye and person to person. The retina, a layer of blood vessels located at the back of the eye, forms an identity card for the indiv...

BACKGROUND Diabetes affects the vascular ocular circulation. Colour Doppler imaging allows for simultaneous two dimensional anatomical imaging and Doppler evaluation of blood flow velocity; with this technique ocular blood flow velocity can be evaluated in normal and diabetic patients. METHODS A prospective study compared blood flow velocity in ocular vessels (ophthalmic artery, posterior cil...

PURPOSE This study investigated the effect of cedilanid on retinal neovascularization in a mouse model of oxygen-induced retinopathy. METHODS Seven-day-old C57BL/6 mice were exposed to 75% ± 1% oxygen for 5 days and were then returned to room air to induce retinal neovascularization. Cedilanid (0.025-0.2 μg) was intravitreally injected into the left eye of each mouse on postnatal day 12 (P12)...

A method is described for measuring mean retinal circulation time in man from serial fundus photographs after injecting fluorescein into a peripheral vein. From densitometric measurements on the photographic images of the retinal vessels an estimate is made of the relative concentration of fluorescein in arterial and venous retinal blood at the time of each picture, and arterial and venous time...

The blood vessels that nourish the inner retina cast shadows on photoreceptors, creating "angioscotomas" in the visual field. We have found the representations of angioscotomas in striate cortex of the squirrel monkey. They were detected in 9 of 12 normal adult animals by staining flatmounts for cytochrome oxidase activity after enucleation of one eye. They appeared as thin profiles in layer 4C...

PURPOSE Endothelin-1 (ET-1), synthesized in vascular endothelial cells, is a potent vasoconstrictor. ET-1-related vascular abnormality has been known to be important in the pathogenesis of glaucoma, especially in normal tension glaucoma. However, the long-term effect of increased vascular ET-1 on the retinal tissue is still unclear. METHODS The mice with overexpression of ET-1 in vascular end...