Showing papers on "Retinal Vein published in 1975"
Journal Article•
TL;DR: Findings indicate that the retinal circulation parallels that of the brain in adjusting to changes in arterial PO2 with compensatory changes in blood flow, which increases considerably in hypoxia and shows a moderate decrease in hyperoxia.
Abstract: The relationship of blood oxygenation to retinal blood flow has been studies in rhesus monkeys Constriction of major retinal arteries and veins during hyperoxia and dilation during hypoxia are demonstrated Together with mean circulation times based on the technique of fluorescein densitometry curves, these data allow an estimation of retinal blood flow, which increases considerably in hypoxia and shows a moderate decrease in hyperoxia These findings indicate that the retinal circulation parallels that of the brain in adjusting to changes in arterial PO2 with compensatory changes in blood flow
142 citations
Journal Article•
93 citations
TL;DR: Despite the return of visual acuity to normal, visual function studies indicate the persistance of defects.
Abstract: The accessibility of high-altitude areas presents the risk of high altitude retinal hemorrhages (HARH). Four cases reported illustrate localized macular, diffuse, and familial incidence of HARH. Fluorescein angiography indicated no leakage, and a superficial retinal location of the hemorrhages. Marked retinal artery and vein dilation occurs. Ophthalmodynamometry showed retinal vascular hypertension in the presence of HARH. The complete resolution of hemorrhages occurs in most cases. Despite the return of visual acuity to normal, visual function studies indicate the persistence of defects.
58 citations
TL;DR: Following occlusion of two major retinal veins in a rhesus monkey, areas of retinal non-perfusion developed and these areas became gradually revascularized over the subsequent 5 months.
53 citations
Journal Article•
42 citations
TL;DR: The hypothesis that an occlusion of the central Retinal artery is an essential prerequisite for haemorrhage formation after central retinal vein obstruction has been investigated by examining the fundus changes in patients with a cilio-retinal arterial circulation; the findings are at variance with the 'combined Occlusion hypothesis'.
Abstract: The hypothesis that an occlusion of the central retinal artery is an essential prerequisite for haemorrhage formation after central retinal vein obstruction has been investigated by examining the fundus changes in patients with a cilio-retinal arterial circulation; the findings are at variance with the 'combined occlusion hypothesis'. Comparisons were made between the pathological features in two retinal capillary beds with independent sources of arterial supply--namely, the central retinal and cilio-retinal arteries--but with an obstructed venous drainage channel common to both--namely, the central retinal vein. The importance of intraluminal pressure changes (as distinct from perfusion changes) in the causation of haemorrhages and oedema after venous occlusion is stressed, and the role of arterial disease in the pathogenesis of venous occlusions is distinguished from its role in determining the sequelae of such occlusions.
35 citations
TL;DR: An optimal balance between acclimatization and subsequent altitude stress appeared to prevent retinal hemorrhage, and factors that intensified the rate or degree of exposure, including rapid ascent and strenuous exertion, appeared to increase the likelihood of hemorrhage.
Abstract: Retinal hemorrhage occurred in 36% of 39 subjects exposed to altitudes at or above 14,200 feet. In subjects with a history of vascular headaches at sea level, there was a higher incidence of and more severe altitude headache, as well as a higher incidence of retinal hemorrhage than among those previously headache-free. In subjects without altitude headache, none had retinal hemorrhage. In subjects with altitude headache, 42% had retinal hemorrhage. A progressive rise in the incidence of retinal hemorrhage was correlated with progressively greater intensity of altitude headache. Factors that intensified the rate or degree of exposure, including rapid ascent and strenuous exertion, appeared to increase the likelihood of hemorrhage. An optimal balance between acclimatization and subsequent altitude stress appeared to prevent retinal hemorrhage. Increased retinal blood flow, retinal vessel engorgement, increased retinal vein and prevenous capillary pressure, and possibly decreased intraocular pressure may contribute to the pathogenesis of retinal hemorrhage.
27 citations
Journal Article•
TL;DR: Changes observed by ophthalmoscopic observation, fluorescein angiography, histologic preparation, and electron microscopy: vascular leakage, vascular occlusion, hemorrhage, and retinal detachment were considered secondary toxic phenomena and did not occur at physiologic prostaglandin concentrations.
Abstract: One dose of each prostaglandin preparation was injected into the vitreous body of the right eye of 64 rabbits. Doses less than 200mug caused no toxicity. Doses greater than 200mug exhibited the following changes observed by ophthalmoscopic observation, fluorescein angiography, histologic preparation, and electron microscopy: vascular leakage, vascular occlusion, hemorrhage, and retinal detachment. Electron micrographs revealed damaged retinal vascular endothelial cells. These changes were considered secondary toxic phenomena and did not occur at physiologic prostaglandin concentrations.
22 citations
TL;DR: Photocoagulation successfully obliterated the retinal holes and prevented extension of theretinal detachments in both cases of patients with rhegmatogenous retinal detachment after tributary retinal vein occlusion.
16 citations
Journal Article•
TL;DR: Fundus examination revealed tortuosity of venules around the macular area and alteration of the pigment epithelium indicating low-grade retinal vein occlusion.
Abstract: A case of unilateral retinal vascular occlusion secondary to the use of oral contraceptives is presented The vision was only slightly affected Fundus examination revealed tortuosity of venules around the macular area and alteration of the pigment epithelium indicating low-grade retinal vein occlusion Periodic ophthalmologic examination is suggested to women on oral contraceptives to prevent serious thromboembolic complications
12 citations
Journal Article•
TL;DR: A case report of retinal vascular occlusion in a woman who had been taking oral contraceptives for 4 years is discussed in this paper, where the patient complained of headaches and blurred vision in her left eye.
Abstract: A case report of retinal vascular occlusion in a woman who had been taking oral contraceptives for 4 years is discussed The patient complained of headaches and blurred vision in her left eye Fundus examination revealed tortuosity of venules around the macular area and alterations of the pigment epithelium which indicated low-grade retinal vein occlusion There were no signs of vascular occlusion or delay in capillary and venous perfusion The presence of intraretinal or subretinal fluid could not be demonstrated Periodic ophthalmological examination to detect early sings of thromboembolic complications is recommended for women taking oral contraceptives
TL;DR: Two cases of central retinal venous thrombosis with gross involvement of the arterial supply to the retina are described and appear to show an exaggerated arterial type of response, and seem to form a distinct clinical entity as opposed to the basically venous insufficiency ofcentral retinal vein thromBosis of the usual type.
Abstract: Two cases of central retinal venous thrombosis with gross involvement of the arterial supply to the retina are described. The iris fluorescein angiography showed massive leakage of dye into the anterior chamber. The iris angiographic findings in 48 cases of central venous thrombosis are compared with those of 19 patients with central retinal artery occlusion. In venous obstruction pupillary and extrapupillary vessels leak both in recent and in long-standing cases, whereas in arterial occlusions extrapupillary leakage occurs exclusively in recent cases. Comparatively, the 2 cases of stagnation thrombosis appear to show an exaggerated arterial type of response, and seem to form a distinct clinical entity as opposed to the basically venous insufficiency of central retinal vein thrombosis of the usual type.
01 Jan 1975
TL;DR: The classical picture of ipsilateral blindness and contralateral paralysis due to carotid and ophthalmic artery occlusion is well known to ophthalmologists but less known that retinal vein thrombosis is much more frequently associated with cerebral stroke than chance would allow.
Abstract: The classical picture of ipsilateral blindness and contralateral paralysis due to carotid and ophthalmic artery occlusion is well known to ophthalmologists. It is less known that retinal vein thrombosis is much more frequently associated with cerebral stroke than chance would allow. The following four patients seen by us in the last two years illustrate the clinical association between these two findings. I would like to describe them briefly.