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At least 1,135 records · Page 63Linked to original sources
PubMed2005

Retinal arteriolar narrowing, hypertension, and subsequent risk of diabetes mellitus.

BACKGROUND: Microvascular disease and hypertension have been linked with risk of diabetes mellitus. We examined the association of retinal arteriolar narrowing, a marker of chronic hypertension, with incident diabetes. METHODS: Prospective cohort study of 3251 nondiabetic persons aged 43 to 86 years living in Wisconsin. The diameters of retinal vessels were measured from baseline retinal photographs of participants. Retinal measurements were summarized as the retinal arteriole-to-venule ratio, with smaller ratios indicating narrower arteriolar diameters. Incident diabetes cases were ascertained at the 5-year and 10-year follow-up examinations. RESULTS: There were 249 incident diabetes cases. Participants with narrower retinal arteriolar diameters had a higher incidence of diabetes (cumulative incidences of 5.1%, 7.0%, 9.2%, and 11.7%, comparing decreasing quartiles of arteriole-to-venule ratio). After controlling for baseline casual blood glucose level, glycosylated hemoglobin level, body mass index, and other risk factors, retinal arteriolar narrowing was significantly associated with risk of incident diabetes (multivariable-adjusted relative risk, 1.53; 95% confidence interval, 1.03-2.27; comparing smallest to largest arteriole-to-venule ratio quartiles). Participants with both hypertension and retinal arteriolar narrowing had a 3-fold higher risk of incident diabetes (multivariable-adjusted relative risk, 3.41; 95% confidence interval, 1.66-6.98) than normotensive participants without arteriolar narrowing. CONCLUSIONS: Retinal arteriolar narrowing is related to risk of incident diabetes. These data suggest a possible link between systemic arteriolar narrowing associated with hypertension and diabetes development.

Adult↗
PubMed1986

Accessory cells in vessels of the paranatal human retina.

Retinas of the paranatal period contain two types of cell clusters that are generally believed to play a role in the developing vasculature. The more posterior cluster consists of angioblastic cells, which undergo lumenization to form the definitive vessels. Anterior to this cluster and separated from it by a distinct boundary are clusters of spindle cells extending a variable distance toward the periphery. These clusters of spindle cells maintain a fixed position relative to the angioblastic masses, without any admixture of the two. The precise function of the spindle cells in the vascularizing process has been a subject of controversy. We found evidence to identify them as glia and to suggest that their role is to provide an energy source for the developing retina as the hyaloid vessels recede and until the retinal vessels take over this function. It further appears that congenital failure of the vessels to develop may result in a persistence of these spindle cells, in the form of hyperplastic glia in the inner layers of the retina. Our study included normal eyes from full-term and premature infants and eyes from patients with retinopathy of prematurity (oxygen-related retinopathy), anencephaly, and other congenital anomalies.

Anencephaly↗
PubMed1994

Localization of collagen type III mRNA in normal human optic nerve heads.

Previous studies using immunocytochemistry and electron microscopy have localized collagen type III (CIII) in the human optic nerve head (ONH). CIII is present in the core of the cribriform plates of the lamina cribrosa and increases with age. In this study, in situ hybridization was used to localize mRNA for CIII in specific cells in human fetal and adult ONH to determine its cellular origin and to provide temporal and regional information on the synthesis of CIII in the ONH. Human ONH from donors with no history of eye disease (16-24 weeks gestation and 6-75 years) were fixed, embedded and sectioned serially. Sections were hybridized with antisense riboprobe for CIII and controls with sense riboprobe and processed for ISH. Immunoperoxidase staining with antibodies against GFAP and von Willebrand factor was used to detect astrocytes and vascular endothelial cells respectively. Fetal ONH: CIII mRNA was localized in most blood vessels throughout the ONH in sections hybridized with antisense probe. The label was localized to endothelial cells of small vessels. Endothelial cells of central retinal vessels were not labeled. In the lamina cribrosa, CIII mRNA was localized to small vessels, but not to astrocytes. Fibroblasts of the peripapillary sclera were labelled with antisense probe. Young-Adult ONH: In the cribriform plates, lamina cribrosa cells hybridized the probe at all ages. Few astrocytes hybridized the probe. Some endothelial cells of small vessels were also labeled. In the insertion region, most vessels were labeled in young ONH, but very few, if any, in old adults. The apparent intensity of hybridization signal associated with blood vessels in adult ONH is markedly reduced with age. No hybridization was observed inside of nerve bundles consistent with the absence of mRNA inside axon and CIII in this location. Localization of mRNA for CIII to blood vessels in fetal lamina cribrosa suggests a vascular origin for CIII in the plates, and perhaps, for lamina cribrosa cells. In young and old lamina cribrosa, localization of CIII mRNA suggests lifelong synthesis of this protein in agreement with age-related increase of CIII in this tissue.

Adolescent↗
PubMedDate not supplied

Case report: indocyanine green dye leakage from retinal artery in branch retinal vein occlusion.

BACKGROUND: Little is known about retinal vascular lesions underlying hemorrhage in the acute phase of branch retinal vein occlusion (BRVO). CASE: A 64-year-old woman presented with a decrease in visual acuity of ten-day duration in her left eye. OBSERVATIONS: At the initial examination, her left fundus showed the typical appearance of BRVO, including retinal bleeding and soft exudates in the lower half of the fundus, after the arteriovenous crossing. Fluorescein angiography showed no detail in the retinal vessels, which were occluded by retinal bleeding. However, in the early phase of indocyanine green (ICG) angiography, ICG dye leaked from the retinal artery at a point proximal to the first bifurcation. In the late phase of ICG angiography, the dye pooled along the retinal artery in a fusiform fashion. One year after laser photocoagulation was performed in the area of the BRVO, ICG dye leakage from the retinal artery had completely disappeared. CONCLUSIONS: These findings suggest that the changes in the retina detected by ICG angiography may have been associated with the onset of BRVO. In patients with acute BRVO, ICG angiography may be used to evaluate retinal arterial lesions covered by hemorrhage and provide useful information.

Capillary Permeability↗
PubMed2003

[Evulsion of the optic nerve following blunt bulbar trauma. Case report and review of the literature].

BACKGROUND: Evulsion of the optic nerve is a rare form of traumatic optic neuropathy. It is a rupture of the optic nerve at the disc without damage of its sheaths occurring in association with a blunt skull trauma or a blunt bulbar trauma. METHOD: We report on a 13-year old girl with complete evulsion of the optic nerve after blunt bulbar trauma and give a literature review. RESULTS: While swinging on a liana the patient had crashed into a tree. The initial examination 3 hours after the accident revealed at the right eye an amaurosis without any afferent reaction of the pupil to light. Ophthalmoscopy displayed a vitreous haemorrhage at the optic disc, peripapillar white retina and interruption of the blood flow of all visible retinal vessels. Fluorescein angiogram showed no retinal perfusion and a detatched retina above the disc. Echographic examination revealed a vitreous haemorrhage at the disc shaped like a mushroom. From the eighth day, examination of the retina became impossible due to disseminating vitreous haemorrhage. After 8 months vitreous haemorrhage had disappeared revealing a white fibrosis at the area of the optic disc. Since first histological description of an optic nerve evulsion by His in 1856, 42 patients with complete and 23 with partial evulsion of the optic nerve were reported in the literature. In our review different mechanisms of injury are discussed. CONCLUSION: Evulsion of the optic nerve is rarely reported. It is possible that it may occur more frequently, because it cannot be seen in blunt or also penetrating bulbar traumas with severe intraocular cloudiness.

Adolescent↗
PubMed1993

[Combined hamartoma of the retina and retinal pigment epithelium. CLinical Aspects and differential diagnosis to other melanocytic processes of the fundus].

BACKGROUND: The combined hamartoma of the retina and the retinal pigment epithelium is a rare but important differential diagnosis of the melanocytic lesions of the fundus. PATIENTS AND METHODS: We present a patient with the typical clinical picture and characteristic fluorescein angiography findings. The case report is followed by the discussion of the differential diagnoses and their specific signs. RESULTS: The combined hamartoma of the retina and the retinal pigment epithelium is a congenital malformation without growth potential, which may lead to a slow reduction of visual acuity due to secondary changes in the vitreoretinal interface followed by retinal traction. The hamartoma shows a typical clinical picture: unnoticed reduction of visual acuity, grayish tumor on the level of the retina with feathery margins, secondary epiretinal proliferation and traction of the neurosensory retina. The fluorescein angiography findings are pathognomonical for the hamartoma: early blockage of the choroidal hyperfluorescence due to the pigmentation of the tumor, a fine network of abnormal retinal capillaries with leakage, epiretinal traction, tortuositas of the larger retinal vessels without leakage. CONCLUSION: The retinal and pigmentepithelial hamartoma can be diagnosed in most of the cases by mere visual inspection. The diagnosis can be confirmed by fluorescein angiography and always has to be included to evaluate the differential diagnoses of all pigmented fundus lesions.

Adult↗
PubMed1992

Bread crumb-flecked retinopathy.

The case of a young girl with bilateral retinal flecks, normal fluorescein angiography results, and normal electrophysiologic findings is reported. The fundus appeared to consist of multiple, scattered, pale, bread crumb-like lesions that seemed to lie deep to the retinal vessels and anterior to the retinal pigment epithelium. The lesions were located outside the posterior pole in the midperiphery, and spared the macula and perimacular areas. The disorder may be associated with anomalies of the central nervous system and extraocular motility. No reports of similarly described fundus lesions have been found in the literature.

Child↗
PubMed1989

Leber's hereditary optic atrophy.

Leber described a particular type of hereditary optic atrophy in 1871. The clinical features of all cases since reported are reviewed. There is characteristically acute visual loss, circumpapillary teleangiectatic micropathy, tortuosity of the retinal vessels and oedema in the retinal nerve fibres. 85% of those affected are male, but affected fathers do not transmit the condition to their children. The exact mode of inheritance is still obscure but it is suggested that inheritance may be mitochondrial; enlarged subsarcolemmal mitochondria in LOA patients have been described. Colour vision defects are observed not only in patients, but also in presumed carriers. Electrophysiological investigations demonstrate optic nerve damage, but are not indicative of any particular pathology. It has been reported that in many cases of LOA the severity of the disease is related to tobacco smoking. Increased cyanocobalamin blood levels in patients and increased cyanide blood levels support this hypothesis.

Electroretinography↗
PubMed1981

[Long-term results of surgical hypophysectomy for diabetic retinopathy (author's transl)].

Between 1969 and 1974, ten insulin-dependent diabetic patients underwent surgical hypophysectomy for rapidly progressive proliferative retinopathy endangering sight. Six to 11 years later, the 7 patients who survived had useful visual acuity and were leading a normal life. The long-term results of hypophysectomy on the eye could be observed in this series of patients with exceptionally long follow up: oedema had subsided, haemorrhagic exsudates and newly formed retinal vessels had disappeared, and the retinal had become hypovascular. However, argon laser photocoagulation has now considerably reduced the indications of surgical hypophysectomy.

Adult↗
PubMed1994

[Rapidly progressive outer retinal necrosis in a patient with acquired immunodeficiency syndrome].

We report a case of rapidly progressive varicella zoster virus retinitis, which is distinct from acute retinal necrosis syndrome. The patient was a 52-year-old male and suffered acquired immunodeficiency syndrome. Two months after the varicella zoster dermatitis in the distribution of the first division of the left trigeminal nerve, pseudodendritic keratitis and iridocyclitis were observed in the left eye. After 5 weeks, multifocal and patchy white exudates were observed in the peripheral deeper layer of the retina in the left eye, but retinal vasculitis in the exudative lesions was slight. Despite systemic administration of acyclovir, white exudates progressed confluently from the periphery to the post pole of the retina and reached the macula in 10 weeks. Eight weeks after the observation of lesions in the left eye, we found the same lesions in the right eye. After the white exudative lesions disappeared, the retina became atrophic and the retinal vessels were narrowed, but no retinal detachment was observed. Recently, Foster and associates described the rapidly progressive outer retinal necrosis as a new entity of varicella zoster virus retinitis in AIDS patients. We think our case was very similar to the rapidly progressive outer retinal necrosis. This case shows that we must carefully follow up the rapidly progressive outer retinal necrosis in the AIDS patients with a varicella zoster dermatitis.

AIDS-Related Opportunistic Infections↗
PubMed1986

Treating avulsed vessels with a temporary balloon buckle.

We treated nine patients with avulsed retinal vessels by first expanding a balloon in the parabulbar space to buckle the vessel temporarily and then applying a laser beam to the avulsed segment. In three patients the avulsed vessel was an artery and in six it was a vein. The avulsion was the only abnormality in three patients; in six it was combined with a retinal break, which was accompanied by a detachment in five. The balloon brought the avulsed portion of the vessel into contact with the retina and the pigment epithelium and made it receptive to laser coagulation. Flow in the vessel could be slowed or stopped while the patient was undergoing laser treatment by further expanding the balloon.

Evaluation Studies as Topic↗
PubMed2003

[Exogenous advanced glycosylation end products induce diabetes-like vascular dysfunction in normal rats: a factor for occurrence of diabetic retinopathy].

OBJECTIVE: To disclose the relationship between the deposition of advanced glycosylation end products (AGE) in the retinal vascular tissues and damage of retinal vessels in diabetic retinopathy. METHODS: Sixteen SD rats aged 2 months were divided into 4 groups, with 4 rats in each group. Rats in normal group received no treatment. Diabetes was induced by AGE in the diabetes group. Rat serum albumin (RSA, 40 mg/kg weight) was administered daily to healthy non-diabetic rats through tail veins for 2 weeks (RSA group). AGE-modified RSA was injected to rats in another group at the same route and dosage (AGE-RSA group). The number of pericytes in retinal capillary vessels was counted 2 weeks later. RESULTS: After two weeks continuous AGE treatment, the average amount of pericytes of capillary vessel per 10 microscope visual field (x 100 magnification) in AGE group (4.31 +/- 0.34) was significantly less than that of RSA group (5.80 +/- 0.48) (P < 0.01). Meanwhile, in the AGE-RSA group, AGE were identified in the retinal vascular tissues by immunohistochemical staining. CONCLUSION: Injection of exogenous AGE into healthy rats induces vascular changes resembling those find in the diabetic retinopathy. AGE might be one of the independent pathogenic factors in the occurrence of diabetic retinopathy.

Animals↗
PubMed1985

Control of ocular blood flow.

The eye has a dual vascular supply. The uveal vessels are distributed within the choroid, the ciliary body, and the iris; and the retinal vessels within the inner parts of the retina. The vascularization of the uvea is very rich and the blood flow is high, which stabilizes the temperature of the eye. The vascularization of the retina is relatively sparse, which is an obvious advantage for the optics. The perfusion pressure in the eye can be defined as the local arterial blood pressure minus the intraocular pressure. Reductions in perfusion pressure, caused by increments in intraocular pressure, or reductions in mean arterial pressure reduce the blood flow in the choroid. In the retina, there are efficient autoregulatory mechanisms that prevent changes in flow within a wide range of perfusion pressures. Stimulation of the cervical sympathetic chain causes vasoconstriction in the uvea, with near-maximal effects as 10 Hz. The sympathetic nerves are not activated during moderate hemorrhage. They apparently prevent overperfusion and breakdown of intraocular barriers under conditions of acute elevation of the arterial blood pressure. Electrical stimulation of the oculomotor nerve causes cholinergic vasoconstriction in the anterior uvea. Near-maximal vasoconstriction is obtained between 10 and 20 Hz. In conscious animals, muscarinic blockade causes vasodilatation in the iris, indicating that there is a basal traffic in the vasomotor fibers of the oculomotor nerve. Electrical stimulation of the facial nerve causes vasodilatation in the uvea that cannot be prevented by muscarinic blockade: near-maximal vasodilatation is obtained between 10 and 20 Hz.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed2005

Expression of angiogenesis-related genes during retinal development.

We assessed expression patterns of angiogenesis-related genes in mouse retina during perinatal vascularization and in adulthood. Vascular endothelial growth factor (vegf) and its receptors flk, flt1, and neuropilins 1 and 2 are expressed in both vascularized and avascular areas. Within the expression domain for vegf, appearance of these receptors is spatially and temporally non-overlapping. Expression of flk, flt1, the matrix metalloproteinase mt1-mmp, and the tissue inhibitor of metalloproteinase timp2, but not of mmp2, mmp9, timp1, or timp3, correlates with inner retinal vascularization. In particular, expression of flk, flt1 and mt1-mmp in the inner retina begins adjacent to the optic nerve head and extends anteriorly during the first week of life, roughly concordant with the growth of retinal vessels. Several genes (vegf, flk, flt1, timp2, possibly mmp9) appear to be expressed by retinal glia.

Animals↗
PubMed1983

[Fluorescence microscopy study of fluorescein in the posterior segment of the eye following local application of drugs].

After local application of gentamicin, dexamethasone and tropicamide to rat eyes, no effect on the permeability or the caliber of retinal vessels was observed, nor any diffusion of fluorescein from the choriocapillaris to the outer retinal layers. The qualitative assessment of fluorescence microscopic preparations (and photographic reproductions of them) is relatively unreliable and has led to confusion in the literature. The results presented here, which to some extent contradict earlier findings published in 1971, are discussed. The authors expect to obtain more accurate results from the quantitative method which they are now using.

Animals↗
PubMed1989

[Measurement of retinal circulation in uveitis of Behçet's and Harada's disease].

In order to investigate retinal circulation in patients with Behçet's disease and Harada's disease, we divided 27 patients into three groups; Behçet's group (8 patients), Harada's group (8 patients) and the control group (11 normal subjects). By means of video-densitometric image analysis of fluorescein angiography, we measured the buildup time (BT), time constant of washout rate (TC) and mean circulation time (MCT) for both the retinal artery and vein. The results were as follows: 1) The BT in Behçet group was slightly prolonged compared to that in the control group, while the BT in Harada's disease was shorter than that in the control group. 2) The TC in both the Behçet's and Harada's groups was significantly prolonged compared to that in the control group. 3) The MCT in both Behçet's and Harada's groups was not significantly different from that in the control group. These results suggest that Behçet's disease cases may have normally and compensatory retinal circulation, whatever vasculitis occurs on retinal vessels. On the other hand, choroiditis in Harada's disease has no influence on retinal circulation.

Adult↗
PubMed2001

Advanced glycation end products in human optic nerve head.

AIMS: To localise advanced glycation end products (AGEs) in human optic nerve head. METHODS: Optic nerve samples from 13 elderly individuals (seven diabetics and six non-diabetics) were obtained at necropsy. Pyrraline, an advanced glycation end product, was immunohistochemically localised in the optic nerve heads. RESULTS: In the diabetic subjects, moderate to intense immunoreactivity for pyrraline was detected in sclera, pia mater, cribriform plates, connective tissues in the optic nerve, and around vessels in the optic nerve and pia mater. Immunoreactivity for pyrraline was also detected around retinal vessels. In the non-diabetic subjects, slight or no immunoreactivity for pyrraline was found in cribriform plates and around the optic nerve vessels. CONCLUSION: Accumulation of AGEs in cribriform plates and around vessels in the optic nerve may contribute to the development of optic neuropathy in diabetic patients.

Aged↗
PubMed1977

Microvascular injection studies in rubeosis iridis and neovascular glaucoma.

Microvascular silicone injection, tissue clearing, and histologic examination were used to demonstrate the origin, distribution, and interconnections of newly formed iris and chamber angle blood vessels in four eyes with rubeosis iridis and neovascular glaucoma associated with diabetic retinopathy and central retinal vessel occlusion. The newly formed iris vessels that formed either a tight, evenly distributed (diabetic) or loose, irregularly distributed (central vessel occlusion) network in the iris originated from the normal iris arteries that were branches of either the major arterial circle or of the perforating branches of the anterior ciliary arteries, and drained into the normal iris and ciliary body veins and occasionally into the paralimbal episcleral veins. These newly formed iris vessels appeared to shunt intravascular fluid from arteries to veins. The newly formed anterior chamber angle vessels that formed tufts and arcades at the trabecular meshwork also originated from the roots of the iris arteries and the ciliary body arteries and connected with the peripheral neovascular iris network. In addition, the circumferentially running angle vessels that coursed within the trabecular meshwork branched into and coursed within a fibrosed Schlemm's canal and into two of its intrascleral collector channels. No open communication between these newly formed vessels and the Schlemm's canal-aqueous outflow system was seen.

Arteriovenous Anastomosis↗