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At least 1,495 records · Page 83Linked to original sources
PubMed1994

Central retinal artery occlusion in a patient with Fabry's disease documented by scanning laser ophthalmoscopy.

Fabry's disease, angiokeratoma corporis diffusum, is an X-linked inborn error of glycosphingolipid metabolism due to lack of activity of the lysosomal enzyme, alpha-galactosidase A, resulting in progressive intracellular deposition of neutral glycosphingolipids in various tissues, including vascular endothelial - and smooth muscle cells. Occlusions of the retinal vessels are rare. We present a case of central retinal artery occlusion in a 25-year-old male with Fabry's disease, documented by fluorescein- and indocyanine green angiography performed by scanning laser opththalmoscopy.

Adult↗
PubMed1986

Vitreal oxygen tension gradients in the isolated perfused cat eye.

Pre-retinal partial pressure of oxygen (PO2) profiles have been measured for the first time in the isolated arterially perfused eye of the cat. The perfusate, fed to the eye under a constant pressure head, contained no haemoglobin or haemoglobin analogue so that the only source of oxygen was in the dissolved form. Maximum oxygen supply is provided by raising perfusate PO2 by equilibration with 100% O2. Periodic measurements of the DC corneal electroretinogram were used as a check on preparation viability. Using oxygen sensitive microelectrodes, oxygen tension profiles were measured in the vicinity of retinal vessels and also in vessel free areas, to determine the effect of the retinal circulation on the local oxygen environment of the vitreous. Results showed that large PO2 gradients exist near retinal arteries whereas more than 1mm away from the retina the PO2 gradient is very shallow. These results are in agreement with those obtained for the in vivo cat eye where the animal is breathed on 100% oxygen. Thus it can be concluded that the isolated perfused eye behaves similarly to the in vivo eye with respect to oxygen distribution and function.

Animals↗
PubMed1999

[A case of central retinal vein occlusion forming the epiretinal membrane].

BACKGROUND: We encountered a patient with central retinal vein occlusion (CRVO) forming an epiretinal membrane (ERM) in a wide area. Generally formation of ERM is rare in CRVO. PATIENT AND METHODS: The patient was a 72-years-old female with ischemic CRVO in the right eye, who had undergone insufficient pan-retinal photocoagulation. Since ERM was formed in a wide area 7 months after the occurrence of CRVO, the patient underwent vitrectomy. RESULTS: Although the patient was elderly, the posterior vitreum had not been detached, and ERM was observed in a wide area from the disk of the optic nerve over the vascular arcade. Since the ERM strongly adhered to the retina, incision of the membrane with vitreous scissors was required. The membrane tissue collected during the operation showed few vascular and cellular components, and consisted of ERM extracellular matrices such as collagen. CONCLUSIONS: In this patient, however, it was probable that not only barrier dysfunction of retinal vessel endothelial cells caused by elevated pressure in the retinal vein and rapid retinal ischemia but also the anatomical feature of the undetached posterior vitreum was involved in the formation of the ERM.

Aged↗
PubMed1999

Retinal venous macroaneurysm associated with premacular hemorrhage.

To report an unusual association of a retinal venous macroaneurysm with premacular hemorrhage in a 50-year-old man, using a case report method. The patient exhibited a dense premacular hemorrhage in the left eye. Fluorescein angiography demonstrated that the source of bleeding was an isolated retinal venous macroaneurysm. The anterior surface of the hematoma was opened with an argon green laser, resulting in rapid clearing of the premacular hemorrhage and improvement in vision. Treatment of the retina surrounding the macroaneurysm to prevent recurrence of bleeding was ineffective to achieve occlusion of the lesion. No recurrent hemorrhage occurred during the observation period. Retinal venous macroaneurysm, a quite rare condition, may be complicated by premacular hemorrhage. Argon green laser may be useful in treating such hemorrhage. Hemorrhagic detachment of the internal limiting membrane or subhyaloid hemorrhage in the macula may occur after retinal vessel rupture with physical exertion (Valsalva retinopathy) or in retinal vascular diseases, such as proliferative diabetic retinopathy, and retinal arterial macroaneurysm. Arterial macroaneurysms are a common, well-described retinal vascular disorder. In contrast to retinal arterial macroaneurysms, retinal venous macroaneurysms are quite rare. In this article we describe a patient who presented with premacular hemorrhage that was caused by a retinal venous macroaneurysm. The hematoma and the macroaneurysm were treated with argon green laser.

Aneurysm↗
PubMed1992

[Effects of carteolol on electroretinograms in isolated perfused cat eye].

Effects of carteolol on ERG b-wave amplitude were investigated in dark adapted isolated perfused cat eyes. Carteolol enhanced ERG b-waves with both strong stimuli that reflect the function of both the rod and cone systems, and weak stimuli that reflect the function of the rod system. These observations suggest the following two ideas i.e.: 1. Carteolol increases the flow in retinal vessels of perfusate. or 2. Carteolol has interaction with retinal beta-adrenergic receptors related to the origin of the ERG b-wave. It is likely that both participate in the intrinsic sympathomimetic activity and the release activity of the endothelium derived relaxing factor of carteolol.

Animals↗
PubMed1991

[Therapy of retinal detachment in Coats' disease].

Coats disease, an idiopathic condition of unknown etiology, includes teleangiectatic and aneurysmatic retinal vessels in association with massive subretinal exudation. Progression to retinal detachment caused by prolonged subretinal exudation means a poor prognosis. Retinal detachment surgery had always been controversial. Twelve patients (aged 7 to 48 years) with retinal detachment and Coats' disease were treated by various operations (cryotherapy, 4X; episcleral buckle, 2X; vitrectomy and gastamponade, 3X; vitrectomy and silicone-oiltamponade, 2X). One case (cryotherapy and cerclage) failed and went on to retinal detachment. In the other 11 cases the retinal was reattached successfully. However, peripheral, small areas remained detached, caused by persistent deposits of subretinal exudation. This means that the underlying Coats' disease is still active and must be treated by laser coagulation. It must also be monitored carefully, to keep an eye on the preretinal vitreous activities leading to detachment.

Adolescent↗
PubMedDate not supplied

[Correlation of changes in the optic disk and retina in primary open-angle glaucoma].

Analysis of seventy-seven monocular photographs of the fundus oculi of normal subjects and patients with various glaucoma stages has brought the authors to a conclusion on the diagnostic value of the symptom of the optic disk 'outlining' vessels, phenomenon of the optic disk 'sinking', phenomenon of retinal nerve fiber 'loss', and reduced number and diameter of the retinal vessels in the patients with initial stages of glaucoma.

Aged↗
PubMed1989

Pseudodrusen of the optic disc. Papilledema simulating buried drusen of the optic nerve head.

The distinction between true papilledema and pseudopapilledema rests on characteristics of the optic disc when examined ophthalmoscopically. Buried disc drusen frequently simulate papilledema and often result in misdirected diagnostic maneuvers in search of a cause for presumed intracranial hypertension. When an elevated optic disc exhibits an irregular, "lumpy, bumpy" border, a diagnosis of buried drusen of the optic nerve is usually made. We report a case with papilledema secondary to increased intracranial pressure in which the margins of the swollen optic disc presented this lumpy, bumpy border characteristic of buried drusen. The lumpy character of the disc border disappeared with resolution of the papilledema, and ultrasonography demonstrated the absence of any buried drusen. Other characteristics of papilledema, including extension of the disc swelling into the peripapillary nerve fiber layer, telangiectasia of the superficial vessels of the optic disc, and obscuration of the retinal vessels as they crossed the margins of the optic disc, provided strong evidence of true papilledema and remain the most reliable findings allowing a distinction between true papilledema and pseudopapilledema.

Adult↗
PubMedDate not supplied

Limitations of color Doppler sonography in the imaging of ocular vessels.

PURPOSE: To describe a case where detection of blood flow in the central retinal artery and the central retinal vein was limited by an artifact evoked by the optic disc drusen. METHODS Case report. RESULTS: During color Doppler sonography, examination of optic disc drusen may generate an artifact--the so-called twinkling artifact--which can simulate blood flow and make evaluation of the central retinal vessels impossible. CONCLUSIONS: Twinkling artifact does not allow evaluation of color Doppler sonography in the imaging of ocular vessels.

Artifacts↗
PubMed1982

Congenital retinal macrovessels.

The clinical and fluorescein angiographic features of seven patients with unilateral, large retinal vessels supplying or draining the macular region, both inferior and superior to the horizontal raphe, are described. All patients had good vision, although two patients also had a concomitant foveolar cyst in the involved eye. Four of the seven eyes had small perifoveolar arteriovenous communications, while three eyes did not. Four eyes also showed abnormal areas of retinal capillary nonperfusion. In addition, delayed drainage of dye from the enlarged vessels was a commonly encountered feature. It is suggested that these congenital anomalies be referred to as retinal macrovessels.

Adult↗
PubMed1990

Twin vessels in familial retinal cavernous hemangioma.

We investigated the presence of twin vessels in two patients and in four of their relatives at risk from one family with autosomal-dominant hereditary cavernous hemangioma of the retina associated with central nervous system involvement. Twin vessels were detected in four of the six patients examined. The proband had bilateral retinal vascular hamartomas with central nervous system involvement but no twin vessels. The proband's mother had vascular hamartomas of the retina and brain with twin vessels. In the other three family members, twin vessels were associated either with retinal cavernous hemangiomas (one patient) or with normal fundi (two patients). Because twin vessels may be an ocular manifestation of von Hippel-Lindau disease, their presence in one of our two patients and in the otherwise healthy three family members suggests that twin vessels may be associated with different retinal vascular hamartomas, including capillary and cavernous hemangiomas.

Adult↗
PubMed2005

[Contractility of human retinal arterioles during oxygen breathing vs. myogenic response].

BACKGROUND: By the use of the retinal vessel analyzer (RVA) it is possible to measure the myogenic response of retinal arterioles to blood pressure increases. Pure oxygen breathing is another method to test the contractility of vessels. The presented study compares these two methods in the same healthy volunteers. METHODS: After a 3-minute baseline measurement 20 healthy volunteers (age: 22 - 58 years) were exposed to 100 % oxygen breathing for 5 minutes. The diameter of an retinal arteriole was measured continuously during that period of time. The very same persons were tested in a 9-minute experiment with isometric exercise to cause a vasoconstriction by an increase in mean arterial blood pressure (MAP). RESULTS: Oxygen breathing resulted in a vasoconstriction of - 7.45 (+/- 2.1) % on average. The same individuals reacted with an MAP rise of 24.0 (+/- 5.9) mm Hg to isometric exercise, answered by a vasoconstriction of - 5.3 (+/- 2.1) %. Both tests were significantly correlated to each other. CONCLUSIONS: Although the two tests trigger different autoregulative responses in the arteriole vasoconstriction due to MAP increases and vasoconstriction as an answer to 100 % oxygen breathing they do correlate at a significant level in the same subjects.

Adult↗
PubMed1992

Fluorescence characteristics of indocyanine green in the normal choroid and in subretinal neovascular membranes.

Indocyanine green angiography with scanning laser ophthalmoscopy is a new supplementary method studying subretinal neovascular membranes. However, it is still controversial as to whether of not exudation of this dye occurs from regular choroidal vessels or such membranes. Fluorescence of the macula area, a parapapillary retinal vein, and of venous blood and plasma was therefore measured with a picture analysis system in five healthy young volunteers. Furthermore, the angiograms of 150 subretinal neovascular membranes were reviewed. Membrane fluorescence was measured in ten exemplary cases and compared with the background fluorescence. The results show that macula fluorescence is detectable much longer than the fluorescence of retinal vessels. However, a comparison with the fluorescence of blood and plasma samples revealed that this late fluorescence must be caused by retinal and choroidal capillaries with a significantly reduced hematocrit. It is not caused by apposition or exudation of indocyanine green. The same was true for the majority of subretinal neovascular membranes. Exudation was rarely detected in membranes that were regularly surrounded by exudates but could be induced by laser coagulation. These observations indicate that exudation occurs only after massive destruction of the endothelial barrier. The results are important for the interpretation of indocyanine green angiograms and for possible photodynamic therapy with this dye.

Adult↗
PubMed2000

Microglial cells in the retina of Carassius auratus: effects of optic nerve crush.

To study the morphology and distribution of the retinal microglial cells of the goldfish retina in normal conditions and after optic nerve crush, we have used the nucleoside diphosphatase (NDPase) technique, applied to whole-mounts or sections, for light and electron microscopy. In normal retinas, two populations of NDPase-positive cells were identified: compact cells associated with the retinal vessels on the vitreal surface of the retina and microglial cells in various retinal layers. The microglial cells had a bipolar or multipolar morphology. Bipolar cells were observed in the nerve fibre layer, and multipolar cells were visualised in the ganglion cell layer (GCL), inner plexiform layer (IPL), and outer plexiform layer. The highest densities of multipolar cells were observed in the IPL layer, where they adopted a regular mosaic-like arrangement in which the occasional spaces were occupied by cells of the GCL. After optic nerve crush, we observed an increase in the number of compact cells associated with the vessels and changes in NDPase activity, morphology, and distribution of the retinal microglial cells. These cells showed an increase in NDPase activity in all retinal layers from day 1 to day 15 after axotomy, and retraction of their processes from day 1 to day 7. In addition, the densities of microglial cells increased in the GCL between 2 and 15 days after axotomy, and decreased in the IPL by day 4 after axotomy. These microglial changes resemble those observed in other regenerating and nonregenerating neuronal systems and may reflect a general response of microglia directed to help the regeneration process.

Acid Anhydride Hydrolases↗
PubMed2001

Retinal vascular architecture is maintained in retinal degeneration: corrosion cast and electron microscope study.

PURPOSE: To demonstrate the changes of the retinal vascular architecture in the diffusely degenerated thin retina. METHODS: Three-week-old weanling Wistar Kyoto rats were divided randomly into two groups. One group (n = 20) was fed a vitamin E-deficient solid diet and the other group (n = 20) was fed a solid rat chow diet. Rats were maintained on their respective diets for 14 months and then killed for scanning electron microscopy of vascular corrosion casts, light and electron microscopy and biochemical determinations. RESULTS: The serum level of vitamin E in the E-deficient rats was 1.0 +/- 0.49 microg/ml, while that in the rats fed a normal diet was 13.7 +/- 1.0 microg/ml (Student's t-test, p = 0.0001). In vitamin E-deficient rats, light microscopy showed degenerated retinas only half as thick as normal. Corrosion casts and scanning electron microscopy revealed that the retinal capillaries of the entire retina were decreased in number and scattered with localised narrowing, calibre irregularity and frequent loop formation. In the posterior pole of the retina, some capillaries clustered into small tortuous knots. However, the two-layered architecture of the capillary network in the retina was maintained. The differences in calibre of retinal capillaries between the vitamin E-deficient and normal rats were statistically significant (p < 0.0001). No remarkable abnormal changes were observed in the large retinal vessels other than arterial calibre differences (p < 0.022). No arteriovenous shunts, crossing defects or microaneurysms were seen. Transmission electron microscopy revealed complete disappearance of the photoreceptor outer and inner segments and nuclei. The retinal pigment epithelium contained lipofuscin granules and retinal capillaries with narrow lumens. The capillary endothelial cells were thickened and had scarce cytoplasmic components with vacuoles and irregularly thickened basement membranes. The capillary pericytes had vacuoles. No abnormalities were seen in the control normal rats. CONCLUSION: These findings indicate that the decrease in retinal capillaries in vitamin E-deficient rats is secondary to retinal degeneration. It was assumed that the morphological changes in the capillary network reflected structural damage to the retinal vascular cells caused by free radicals and lipid peroxides generated by oxidation. However, even in such severe degeneration the retinal vascular architecture, including the main artery and vein and two-layer capillary networks, was maintained. This is may be because of the basic anatomical arrangement of the blood vessels.

Animals↗
PubMed2004

Simvastatin inhibits leukocyte accumulation and vascular permeability in the retinas of rats with streptozotocin-induced diabetes.

Leukocytes play important roles in the pathogenesis of diabetic retinopathy. Recently, 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitors have been reported to exert various effects in addition to their lipid-lowering ability. We investigated the effects of simvastatin, a 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitor, on leukocyte-induced diabetic changes in retinas. Diabetes was induced in Long-Evans rats with streptozotocin, and simvastatin administration was begun immediately after the induction of diabetes. Two weeks of treatment with simvastatin suppressed significantly the number of leukocytes adhering to retinal vessel endothelium and the number of leukocytes accumulated in the retinal tissue by 72.9% and 41.0%, respectively (P < 0.01). The expression of intercellular adhesion molecule-1 (ICAM-1) and the CD18 (the common beta-chain of ICAM-1 ligands) were both suppressed with simvastatin. The amount of vascular endothelial growth factor in the retina was attenuated in the simvastatin-treated group. To evaluate the effects of simvastatin on leukocyte-induced endothelial cell damage, vascular permeability in the retina was measured with fluorescein-labeled dextran. Treatment with simvastatin markedly reduced retinal permeability (P = 0.014). This suggests that simvastatin attenuates leukocyte-endothelial cell interactions and subsequent blood-retinal barrier breakdown via suppression of vascular endothelial growth factor-induced ICAM-1 expression in the diabetic retina. Simvastatin may thus be useful in the prevention of diabetic retinopathy.

Animals↗
PubMed2001

PCR-positive tubercular retinal vasculitis: clinical characteristics and management.

BACKGROUND: Inflammation of retinal vessels is a known association of systemic tuberculosis. Patients with retinal vasculitis are subjected to extensive but unrewarding systemic workup. Polymerase chain reaction (PCR) is now commonly used to detect DNA of infective organisms including Mycobacterium tuberculosis. This study was undertaken to characterize the clinical characteristics of PCR-positive tubercular retinal vasculitis, so as to determine the clinical presentation, associated systemic features, management, and course of this form of vasculitis. METHODS: The clinical records of 13 patients seen between 1997 and 1999 with the diagnosis of PCR-positive tubercular retinal vasculitis from the aqueous or vitreous humor were reviewed. Recorded data included age, sex, race, visual acuity, anterior and posterior segment findings, and results of diagnostic evaluations. All received antituberculosis therapy with or without concomitant corticosteroids. Laser scatter photocoagulation was done in eyes with neovascularization. One eye with vitreous hemorrhage was subjected to pars plana vitrectomy. RESULTS: There were 9 (69.2%) male and 4 (30.7%) female patients with a median age of 20 years. The disease was bilateral in seven. The most consistent finding was the presence of vitritis in all the eyes followed by vitreous snowball opacities in 17 eyes (89.4%), neovascularization in 11 eyes (57.8%), retinal hemorrhages in 10 eyes (52.6%), neuroretinitis in 10 eyes (52.6%), focal choroiditis in 9 eyes (47.3%), vitreous/preretinal hemorrhage in 5 eyes (26.3%), and serous retinal detachment in 3 eyes (15.7%). Over a median follow-up of 12 months, all showed resolution of vasculitis with no recurrences. CONCLUSIONS: Polymerase chain reaction-positive tubercular retinal vasculitis had varied associated fundus findings. Its recognition is important so as to order only relevant diagnostic tests.

Adolescent↗
PubMed2005

A detailed study of the phenotype of an autosomal dominant cone-rod dystrophy (CORD7) associated with mutation in the gene for RIM1.

AIM: To characterise the phenotype of an autosomal dominant cone-rod dystrophy (CORD7) associated with the Arg844His mutation in RIM1. METHODS: Eight members of a four generation, non-consanguineous British family were examined clinically and underwent electrophysiological testing, automated dark adapted perimetry, dark adaptometry, colour vision assessment, colour fundus photography, fundus fluorescein angiography (FFA), and fundus autofluorescence (AF) imaging. RESULTS: The majority of affected individuals described a progressive deterioration of central vision, night vision, and peripheral visual field usually between the third and fourth decades. The visual acuity ranged from 6/6 to 3/60. Colour vision testing showed mild to moderate dyschromatopsia in the majority of individuals. Fundus changes comprised a range of macular appearances varying from mild retinal pigment epithelial (RPE) disturbance to extensive atrophy and pigmentation. In some individuals retinal vessels were attenuated and in two subjects peripheral areas of retinal atrophy were present. An absent or severely reduced PERG was detected in all subjects, indicative of marked macular dysfunction. Full field ERG showed abnormal rod and cone responses. AF imaging revealed decreased macular AF centrally surrounded by a ring of increased AF in the majority of individuals. "Bull's eye" lesions were present in two individuals, comprising of a ring of decreased perifoveal AF bordered peripherally and centrally by increased AF. Photopic sensitivity testing demonstrated elevated central visual field thresholds with additional superior greater than inferior peripheral field loss. There were rod and cone sensitivity reductions in the central and peripheral visual fields, with the inferior retina being more affected than the superior. CONCLUSIONS: The detailed phenotype is described of the autosomal dominant cone-rod dystrophy, CORD7, which is associated with a point mutation in RIM1, a gene encoding a photoreceptor synaptic protein. The pattern of disease progression and long term visual outcome facilitates improved genetic counselling and advice on prognosis. Such phenotypic data will be invaluable in the event of future therapy.

Adolescent↗