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At least 1,351 records · Page 75Linked to original sources
PubMed1990

Retinal vasculitis with multifocal retinochoroiditis.

We found a multifocal retinochoroiditis in 16 patients (13 female, 3 male). Patients also showed vitreous cells, in some cases pronounced retinal vasculitis, cystoid macular edema and papilledema. The patients ranged in age from 62 to 77 years. The anterior segment was involved in 13 cases. One patient demonstrated subretinal neovascularisation in both eyes. Fluorescein angiograms showed leakage from the retinal vessels, papilledema, macular edema and subretinal neovascularisation. A convincing classification of the described changes within any known disease entity was impossible. The findings most closely resembled a disease described by Dreyer and Gass in 1984 as 'multifocal choroiditis and panuveitis'.

Aged↗
PubMed2005

Anastomotic vessels remain viable after photodynamic therapy in primate models of choroidal neovascularization.

PURPOSE: Anastomotic vessels in exudative age-related macular degeneration (AMD) represent a serious clinical feature that reportedly does not respond well to either photocoagulation or photodynamic therapy (PDT). Anastomoses also occur in various animal models of choroidal neovascularization (CNV). In the present study, anastomotic vessels and their patency were evaluated in two primate CNV laser-trauma models after PDT, by using two novel photosensitizers. METHODS: In cynomolgus (Macaca fascicularis) and squirrel (Saimiri sciureus) monkey eyes (n = 20), matrix placement of laser photocoagulation sites elicited CNV as a component of the development of fibrovascular tissue (FVT). FVT sites received PDT according to specific drug infusion and laser light treatment parameters. FVTs and anastomoses were evaluated by fundus photography, fluorescein angiography, and histologic examination. RESULTS: Anastomoses averaged approximately 48% of FVT sites, with greatest occurrence in the macaque. Although PDT with each photosensitizer effectively produced FVT closure, both retinal vessels and anastomoses remained patent. CONCLUSIONS: Although PDT is effective in closing the choroidal neovascularization in FVT, this technique was ineffective in occluding anastomotic vessels and their associated tributaries within the mid- to proximal retina. Various factors (vascular diameter, composition, blood flow, orientation) may contribute to continued anastomotic patency. By convention, such vessels would typically be defined as chorioretinal anastomoses (CRAs); however, continuing studies suggest the possibility that these neovessels constitute dual-origin hybrids. Regardless of origin, viable anastomoses provide one potential mechanism for revascularization to occur after PDT and may help to explain why CRAs are considered a poor prognostic sign in patients with AMD.

Animals↗
PubMed1997

[Intraocular metastasis of bronchial carcinoma in a cat].

A rare case of a ten-year-old neutered male Persian cat is described, in which metastasis of a pulmonary adenocarcinoma into the choroid of the right eye had led to visual impairment and major ophthalmoscopically detectable changes of the fundus. These were a generalized hyporeflectivity of the tapetal fundus due to retinal edema with multiple areas of retinal detachment and also severe edema of the papilla, furthermore an increased tortuosity and congestion of the retinal vessels. While the diagnosis of a primary lung tumor could be made intra vitam based on the result of an x-ray examination, the neoplastic nature of the fundic lesions could only be confirmed by histopathologic examination.

Adenocarcinoma↗
PubMed1997

Toward robot-assisted vascular microsurgery in the retina.

BACKGROUND: Experimental protocol in our laboratory routinely requires the precise placement of instruments at, or near, the retina. Although manipulators for placing an instrument within the eye presently exist, none of the designs were satisfactory due to limitations on size, accuracy and operability. To overcome these limitations, we have developed a novel six degree of freedom manipulator designed specifically for retinal microsurgery. METHODS: The manipulator is parallel in structure and provides submicrometer positioning of an instrument within the constrained environment of the eye. The position of an instrument attached to the manipulator is commanded by the operator using a hand-held trackball. A computer controller interprets the trackball input and moves the manipulator in an intuitive manner according to mathematically constrained modes of operation. RESULTS: Over 50 retinal vessels in the live, anesthetized cat have been successfully cannulated for pressure measurement and drug injection using the described manipulator and micropuncture techniques. The targeted vessels ranged in internal diameter from 20 to 130 microns. CONCLUSION: This device has applications in microsurgery where tremor and fatigue limit the performance of an unaided hand and where mechanically constrained manipulators are inappropriate due to size and operative constraints.

Animals↗
PubMed1976

Chorioretinal anastomoses after argon laser photocoagulation.

Communication between the retinal and the choroidal circulation occurred in one case of proliferative diabetic retinopathy and one case of Leber's disease (multiple miliary aneurysms) after argon laser photocoagulation treatment to eliminate abnormal retinal vasculature. In both instances rapid-sequence fluorescein angiography documented the choroidal origin of the anastomoses. Such anastomoses developed in areas where an excessively dense laser beam aimed at occluding retinal vessels presumably destroyed the underlying Bruch's membrane and permitted invasion of the retina by fibrovascular growth from the choriod. The occurrence of such growths is a potential complication of argon laser photocoagulation directly related to the power density used.

Adult↗
PubMed1982

Outer retinal ischemic infarction--a newly recognized complication of cataract extraction and closed vitrectomy. Part 1. A case report.

This report describes a peculiar syndrome occurring as a complication of cataract extraction. The syndrome is characterized initially by (1) acute loss of central and paracentral vision discovered usually on the first postoperative day; (2) diffuse and patchy whitening of the outer retinal layers in the posterior fundus; (3) normal angiographic retinal and choroidal appearance and circulation time; (4) a peculiar polygonal pattern of fluorescein staining of the pigment epithelium and outer retina in the area of retinal whitening, and followed later by (5) clearing of the retinal whitening and mottled changes in the pigment epithelium; (6) partial recovery of the central visual field; and (7) preservation of normal optic disc and retinal vessel caliber. Prolonged elevation of the intraocular pressure sufficient to obstruct choroidal blood flow occurring during the use of intraocular volume-reducing devices before surgery, during phakoemulsification or closed vitrectomy is postulated as the major cause of this complication.

Adolescent↗
PubMed1987

Subretinal neovascularization from the retina in radiation retinopathy.

In a 66-year-old woman with radiation retinopathy, subretinal neovascularization was present, originating from telangiectatic retinal vessels in the macular area. The patient showed no clinical or histologic evidence of age-related macular degeneration or other conditions that may have contributed to the subretinal neovascularization.

Aged↗
PubMed1979

Retrolental fibroplasia.

Retrolental fibroplasia is more accurately referred to as retinopathy of prematurity. Host factors most clearly incriminated are the maturity of the infant and the time in oxygen therapy. A continuum of retinopathy ranges from abnormal arborization of terminal retinal vessels to a detached retina incorporated in a cicatrix behind the lens. Every high-risk infant should be examined by indirect ophthalmoscopy prior to discharge from the nursery. A thorough knowledge of the natural course of the disease is essential because many cases will resolve spontaneously.

Humans↗
PubMed2006

Retinal vascular abnormalities and prevalence of age-related macular degeneration in adult Chinese: the Beijing Eye Study.

PURPOSE: To evaluate whether retinal vessel abnormalities are associated with early or late age-related macular degeneration (AMD) in adult Chinese. DESIGN: Population-based prevalence study. METHODS: The Beijing Eye Study included 4439 (83.4%) subjects of 5324 living in a rural area or urban region of Greater Beijing, age older than 40+ years, and invited to participate. The participants underwent a detailed ophthalmic examination, including fundus photography. The photographs were graded using the Wisconsin Age-Related Maculopathy Grading system for evaluation of AMD, and using the Atherosclerosis Risk in Communities protocol for assessment of retinal vascular abnormalities. We examined focal and generalized arteriolar narrowing, arteriolar sheathing, and arteriovenous crossing abnormalities. RESULTS: Fundus photographs were available for 8655 eyes of 4376 (98.6%) subjects. Neither early nor late AMD was significantly (P > .15) associated with any of the retinal vascular abnormalities. CONCLUSIONS: Retinal vascular abnormalities are not markedly associated with the prevalence of early or late AMD.

Adult↗
PubMed1983

Retinopathy of prematurity: a new look at an old disease.

The neovascular changes of the retinopathy of prematurity can occur in premature infants in three settings: (1) when high levels of supplemental oxygen are administered, neovascularization usually commences shortly after cessation of oxygen therapy; (2) when supplemental oxygen is given for long periods of time, neovascularization can develop while the infant is still receiving oxygen; and (3) neovascularization can occur without exposure to any supplemental oxygen. We propose a model which can explain the occurrence of the retinopathy of prematurity in all these settings. Our model demonstrates that whenever the retinopathy of prematurity occurs, arterial oxygen levels are inappropriately high in relation to the stage of retinal vessel development, even in premature neonates not given supplemental oxygen. The inhibitory effect of these elevated oxygen tensions upon carbon dioxide removal is indicated as a possible cause of neovascularization by leading to tissue acidosis and vasodilatation.

Carbon Dioxide↗
PubMed1985

[Hypothesis on the pathogenesis of the papillary dysversion syndrome].

The tilted disc syndrome is an ocular anomaly characterized by dysversion of the optic nerve head, congenital crescent, vessel anomalies, ectasia and depigmentation of the infero-nasal fundus. Its pathogenesis is not known, but there are many theories as to its origin. The most convincing one links the tilted disc syndrome to an anomalous closing of the embryonic fissure. However this hypothesis does not adequately explains the origin of all the anomalies found in the syndrome. In this paper a new theory is suggested. The ganglion cell fibres of the infero-nasal retina could be misdirected toward the orbit through an anomalous embryonic fissure. In this way the fibres could not reach their central connections and degenerate. The hypoplasia of the infero-nasal quadrant of the eye could originate from the anomalous closing of the embryonic fissure and from the atrophy of the ganglion fibres; the crescent from the lack of fibres in the inferior optic disc; the anomalous appearance of the optic nerve head and the retinal vessels from a shifting of the disc upward due to the imbalance between the ganglion cell fibres coming from the superior and inferior retina.

Choroid↗
PubMed1986

Diabetic macular edema. A review.

Diabetic macular edema can be classified into a focal variety, characterized by focal leakage from microaneurysms, often with accumulation of extravascular lipoprotein in a circinate pattern around the focal leakage, and a diffuse variety, with diffuse leakage from retinal vessels often accompanied by cystoid macular changes. Laser photocoagulation is directed at microaneurysms for focal leakage and is applied in a grid pattern for diffuse leakage. Several prospective randomized clinical trials have shown that laser-treated eyes fare better than untreated eyes: there is a higher rate of modest visual improvement and a lower rate of visual deterioration in eyes treated with laser photocoagulation. In patients with diabetic macular edema, especially the diffuse variety, systemic factors also may play a pathogenic role. Fluid retention and hypertension due to cardiovascular and renal disease exacerbate retinal capillary leakage. Correction of systemic abnormalities (reduced blood pressure, diuresis) may reduce macular edema and should be included as part of the total management of patients with diabetic macular edema.

Clinical Trials as Topic↗
PubMed1983

Ganglion cell topography in human fetal retinae.

Whole-mounted human fetal retinae of gestational ages 14-40 weeks have been studied. These preparations clearly show the distribution of retinal ganglion cells or their precursors across the retina, and the pattern of the retinal vessels and vessel primordia. The ganglion cell layer is present at 14 weeks of gestation and distribution of cells in this layer (ganglion cell precursors) is at first uniform. Ganglion cell density gradients that foreshadow those seen in the adult retina become evident by about 20 weeks gestation. Both mature ganglion cells and precursor cells are present in retinae at about 24 weeks and precursor cells are still seen in the peripheral parts of the retina at about 30 weeks of gestation. The development of mature ganglion cells would appear to coincide with the establishment of retinal circulation, and proceeds in centrifugal sequence from central retinal.

Gestational Age↗
PubMed1998

A data reduction scheme for improving the accuracy of oxygen saturation calculations from spectrometric in vivo measurements.

A developing tool in ophthalmological research and practice is the study of the oxygen saturation in retinal vessels because this measurement contains important diagnostic information about the metabolism at the human ocular fundus. Imaging spectrometry enables locally resolved measurements of the oxygen saturation simultaneously in arteries and veins. The vessel reflex, imaging errors of the detection system and the noise of the signal result in substantial uncertainties in the calculated data. We present a data processing method for the improvement of the primary information leading to a reduction of the uncertainties of the derived oxygen saturation.

Biometry↗
PubMed1988

Leakage of blood-retinal barrier due to damaging effect of protamine sulfate on the endothelium.

The effect of the polycations, protamine sulfate and poly-L-lysine, on the blood-retinal barrier of rat retinal vessels were studied by retrograde perfusion through the aorta or by intracarotid perfusion of the polycation followed by the protein tracer, hemoglobin. Protamine sulfate induced swelling of cytoplasmic organelles and diffuse staining of many endothelial cells by tracer molecules which subsequently entered the subendothelial and perivascular areas. Polylysine caused some diffuse staining but no leakage of tracer through the endothelial cell. Occasionally, tracer was found in the interendothelial junction after protamine perfusion. The results indicate that surface charge is important for maintaining membrane integrity of the endothelial cells and that breakdown of the blood-retinal barrier may be due to the cytotoxic effect of protamine on the endothelial cell.

Animals↗
PubMed1995

Fundus imaging in patients with cataract: role for a variable wavelength scanning laser ophthalmoscope.

AIMS: An investigation was carried out to compare the image quality of the ocular fundus obtained clinically, photographically, and with the scanning laser ophthalmoscope (SLO) at visible and infrared wavelengths in patients with significant cataract. METHODS: Nineteen patients admitted for routine cataract extraction were examined clinically by two independent observers to ascertain cataract type and clarity of fundus view with an indirect ophthalmoscope. Fundus photography and both confocal and direct (non-confocal) SLO imaging at 590 nm, 670 nm, and 830 nm were carried out after pupillary dilatation. Images obtained were graded independently using a recognised grading system. RESULTS: Quality of SLO images appeared to be superior to indirect ophthalmoscopy (p < 0.01) and fundus photography (p < 0.001) when graded subjectively. Quantitative analysis of contrast of retinal vessels demonstrated significantly higher contrast for the SLO compared with digitised fundus photographs at all wavelengths tested (p < 0.001), with highest contrast at 590 nm. Use of a confocal aperture significantly improved vessel contrast but may reduce overall image intensity. CONCLUSIONS: Scanning laser ophthalmoscopy may offer a method to observe and record fine fundus detail in patients who have marked cataract.

Cataract↗
PubMed2002

A goniolens for clinical monitoring of the mouse iridocorneal angle and optic nerve.

PURPOSE: Due to the increasing importance of mouse models and mouse genetics in ophthalmic research, we have developed a goniolens for mice. METHODS: The size and basic design parameters of a human goniolens were adapted to the mouse eye. RESULTS: The goniolens is straightforward to use and allows non-invasive visualization of the structures of the anterior chamber angle, including Schlemm's canal, trabecular meshwork, iris and anterior surface of the peripheral ciliary body. Goniophotography using the mouse lens allows documentation of anterior chamber angle abnormalities, and facilitates comparisons of changes to these structures in the same eye over time. In addition, high quality magnified views of the optic nerve, retinal vessels and posterior retina are easily obtained. CONCLUSIONS: This goniolens is an important new tool for studying the genetic and clinical etiology of anterior segment dysgenesis and glaucoma in mice.

Animals↗
PubMed1975

Color angiography and angioscopy.

The authors present the results of their color fluorescein angiographies carried out with a pocket retinograph equipped with new interferential filters. After the graphic examination, they propose to use these same filters mounted on different instruments for binocular and monocular angioscopy. Their results show that retinal vessels are translucid and that their color changes according to their background. The authors termed this change 'versicolored effect'. Moreover, color angiography with these new filters eliminates pseudofluorescence and adds to the fluoroscopic examination an element of analytic perfection, thus giving a new opening to differential diagnosis in endo-ocular diseases.

Color↗