Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “RETINAL VESSELS”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,315 records · Page 73Linked to original sources
PubMed1997

Ocular fundus morphology in preterm children. Influence of gestational age, birth size, perinatal morbidity, and postnatal growth.

PURPOSE: To determine the influence of gestational age, birth size, perinatal morbidity, and postnatal growth on fundus morphology in preterm children using digital image analysis of fundus photographs. METHODS: Thirty-nine preterm children (mean postmenstrual gestational age, 29.1 weeks; range, 24.6 to 32) were included in the study. Thirty-nine healthy children, born at term, were used as control subjects. Fundus photographs were obtained at a mean age of 4.8 years (preterm) and 6.1 years (control subjects). RESULTS: There was no difference in optic disc, excavation, or peripapillary crescent area between the two groups. In the group of preterm children, a large optic disc size was associated with a low birth weight (rs = -0.29, P = 0.07), duration of assisted ventilation (rs = 0.43, P = 0.006), and number of blood transfusions (rs = 0.33, P = 0.04). The girls born prematurely showed a negative relation between the length of gestation and the area of the optic disc (r2 = 0.28, P = 0.009). No such relation was found in boys. The preterm children had increased tortuosity of retinal vessels (P < 0.001 and P < 0.002 for arteries and veins, respectively) and reduced number of vascular branching points (P < 0.001) compared with those of the control subjects. There were no associations between these vascular abnormalities and the perinatal and postnatal variables studied. CONCLUSIONS: No difference in optic disc morphology between preterm children and control subjects was found. However, preterm birth seems to affect the retinal vascular pattern close to the optic disc, independently of retinopathy of prematurity. Among the girls born preterm, optic disc size was negatively correlated to gestational age.

Birth Weight↗
PubMed1988

Ocular findings in partial trisomy 10q syndrome.

We examined three siblings with partial trisomy 10q born to a mother carrying a balanced translocation between chromosomes 4 and 10. Our patients had many of the phenotypic abnormalities characteristic of this syndrome, and their chromosomal abnormality was confirmed by karyotypes of peripheral blood lymphocytes. Two ophthalmoscopic abnormalities not previously reported in this syndrome were noted in our patients. One child had bilateral enlarged, gray optic disks with elevated, blurred margins and distended retinal vessels. Another child had bilateral punctate yellow deposits scattered around the macula and optic disk.

Adolescent↗
PubMed1996

Correlation between enhanced vascular permeability, up-regulation of cellular adhesion molecules and monocyte adhesion to the endothelium in the retina during the development of fatal murine cerebral malaria.

The relationships between increased vascular permeability to protein, monocyte adherence to the endothelium, and expression of the cell adhesion molecules, intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) in the central nervous system microvasculature were studied during the progression of fatal murine cerebral malaria. CBA mice were inoculated with Plasmodium berghei ANKA, and changes in the retinal microvasculature were examined on days 3, 5, and 7 postinoculation (p.i.). Evans blue dye and horseradish peroxidase (HRP) were administered intravenously to assess vascular permeability to macromolecules macroscopically and by light and electron microscopy. ICAM-1 and VCAM-1 expression were examined by immunohistochemistry. HRP leakage into the retinal parenchyma was seen macroscopically at a low level on day 3 p.i., increasing progressively at day 5 (the earliest time at which cerebral symptoms were observed) and day 7 (the day on which animals showed severe behavioral abnormalities and died). The inner retinal vascular plexus showed a slight increase in vascular permeability to intravenous Evans blue at day 3 p.i. and congestion, monocyte adherence to the endothelium, and increased vascular permeability to both Evans blue and HRP at day 7 p.i. Electron microscopic observations were consistent with these findings and also revealed disrupted light junctions and the coating of monocytes and endothelium with HRP at day 7 p.i. Immunohistochemical staining and densitometry showed a progressive increase from day 3 to day 7 p.i. in the densities of ICAM-1 and VCAM-1 on the venular endothelium of the inner retinal vascular plexus, with the appearance of adherent ICAM-1+ monocytes at the terminal stage of the disease. None of the pathological changes associated with the inner retinal plexus were seen at any stage in the outer retinal plexus. These results suggest the following sequence of events in the inner retinal vessels, particularly the venules, during the progression of fatal murine cerebral malaria: 1) a mild increase in vascular permeability at approximately day 3 p.i., 2) a progressive increase in endothelial expression of the cell adhesion molecules ICAM-1 and VCAM-1, commencing at approximately day 3 p.i., 3) monocyte adhesion to the endothelium starting at approximately day 5 p.i., and 4) frank disruption of endothelial integrity at the terminal stage (day 7 p.i.), leading to edema and hemorrhage. Similar changes in cerebral vessels may underlie the neurological complications of the disease.

Animals↗
PubMed1976

Congenital anomalies of the optic disk.

Six patients had congenital anomalies of the optic disk: epipapillary fibrous tissue, peripapillary pigmentary disturbance, and anomalies in the size of the optic disk and in the retinal vessels. Congenital anomalies of the optic disk form a spectrum in which many of the ophthalmoscopic features are shared and in which visual function varies.

Adolescent↗
PubMed1999

Increased vasodilatory prostaglandin production in the diabetic rat retinal vasculature.

PURPOSE: This study was undertaken in order to investigate whether the production of vasodilatory prostaglandins is increased in the retinal vasculature of the diabetic rat. METHODS: Diabetes was induced in male Sprague-Dawley rats using streptozotocin. Diabetic rats were left uncontrolled for 3-4 weeks or were treated with insulin replacement throughout the period of diabetes. Control rats were age-matched. Retinal vessels extracted from retinae removed at sacrifice were incubated in a physiological salts solution. Prostaglandin E and prostaglandin I2 were measured in collected medium. RESULTS: The production of both prostaglandin E and prostaglandin I2 by blood vessels isolated from the retina was increased by approximately 40% in streptozotocin-diabetic rats, compared to controls, within 4 weeks of the onset of diabetes. This increase was reversed by treatment of streptozotocin-diabetic rats with insulin. The increase in prostaglandin production was not due to alteration in the maximal capacity of cyclooxygenase enzyme. CONCLUSIONS: Increased production of vasodilatory prostaglandins occurs in the rat retinal vasculature early in diabetes. Prostaglandins may contribute to altered retinal hemodynamics in early diabetic retinopathy.

Animals↗
PubMed1975

Serum thyroxine in the early diagnosis of carbon disulfide poisoning.

Serum thyroxine and blood lipids were assayed in 45 subjects exposed to carbon disulfide (CS2). A highly significant statistical reduction of thyroxine in relation to the exposure time was found and the levels appeared lower in the subjects with retinal vessel alterations. A significant interrelation between cholesterol and serum thyroxine was also evidenced. Serum thyroxine assay is suggested as a reliable test in the early diagnosis of CS2 poisoning.

Adult↗
PubMed1990

Familial vascular retinopathy. A preliminary report.

We describe a new hereditary syndrome with an autosomal dominant mode of inheritance, with vascular retinopathy, migraine and Raynaud's phenomenon as the most striking features. The retinopathy is characterized by tortuosity and variable caliber of the retinal vessels, haemorrhages, telangiectases and both central and peripheral vascular occlusions, leading finally to a proliferative retinopathy.

Fluorescein Angiography↗
PubMed1999

Optic nerve morphology may reveal adverse events during prenatal and perinatal life--digital image analysis.

OBJECTIVE: To evaluate optic nerve morphology in children with various conditions caused by adverse events during prenatal and/or perinatal life and to investigate whether optic nerve morphology can reveal brain lesions associated with these conditions, as well as provide insight into the etiology and timing of the prenatal and perinatal damage. METHODS AND PATIENTS: A digital image analysis technique was used to analyze fundus photographs. One hundred healthy Swedish individuals of various ages from childhood to adolescence constituted a reference group. The following patient groups were chosen to represent various clinical conditions affecting the newborn or fetus at different stages of development: children born preterm (N = 39), children with fetal alcohol syndrome (FAS [N = 16]), children with periventricular leukomalacia (PVL [N = 17]), and children with septo-optic dysplasia (SOD [N = 6]). RESULTS: Preterm children without known brain lesions demonstrated normal optic disk morphology but abnormal retinal vascular pattern; children born preterm with an acquired brain lesion late in gestation (PVL) demonstrated normal disk size with enlarged cups in addition to the abnormal vascular pattern. Children with prenatal alcohol exposure (FAS) had a subnormal optic disk area with increased tortuosity of both arteries and veins, whereas children born at term with an early acquired brain lesion (SOD) had a markedly reduced optic disk area with isolated tortuosity of the retinal veins. CONCLUSIONS: Evaluation of optic nerve morphology, by digital image analysis, demonstrated that differences in ocular fundus morphology were correlated with differences in etiology and timing of the adverse event occurring in prenatal and perinatal life. In addition, digital image analysis may be a helpful tool for understanding variations in optic nerve and retinal vessel morphology and their relationship with central nervous pathology.

Adolescent↗
PubMed1985

[Pathogenesis of retinopathy in acute pancreatitis].

Several cases of ischemic damage to the retina associated with acute pancreatitis have been reported since 1975. The retinal disease is said to be caused by fat embolism of retinal vessels. However, since occlusions of blood vessels do not adequately explain the severe morphological changes and malfunctions of the retina, other etiological influences or a combination of them must be considered for this ophthalmological complication.

Acute Disease↗
PubMed2000

Pentoxifylline inhibition of vasculogenesis in the neonatal rat retina.

PURPOSE: The zeta isozyme of protein kinase C (PKC) is essential for activation of the transcription factor nuclear factor (NF)kappaB and transcription of vascular endothelial growth factor (VEGF). This study examined the antiangiogenic potential of an existing drug, pentoxifylline (PTX), which inhibits PKC-dependent activation of NFkappaB and is reported to prevent hypoxia-induced expression of VEGF. METHODS: Neovascularization was induced by maintaining neonatal rats for 10 full days in 80% oxygen, interrupted daily by 30 minutes in room air followed by a progressive return to 80% oxygen. On experimental day 11, they were placed in room air until they were killed on day 17. Daily intraperitoneal injections of PTX in saline (25 or 75 mg/kg per day), or saline alone, were administered from day 6 through day 16. Retinal neovascularization was scored, and avascular areas (AVAs) were measured in ADPase stained retinas. RESULTS: PTX inhibited radial extension of retinal vessels, causing increases in AVA of 65% (P < 0.01) and 33% (P < 0.15) at the lower and upper doses, respectively. A significant increase in mean neovascular score was seen at the lower dose (P < 0.0001), but analysis of variance indicated that neovascularization was strongly and positively influenced by the AVA (P < 0.0001) and only weakly stimulated by PTX (P < 0.05). CONCLUSIONS: Systemic PTX significantly inhibited VEGF-mediated retinal vasculogenesis, but was not effective in reducing neovascularization in the oxygen-exposed neonatal rat.

Animals↗
PubMed1988

Vitrectomy for nondiabetic vitreous hemorrhage. Not associated with vascular disease.

Forty-nine consecutive eyes with nonclearing vitreous hemorrhage not associated with retinal or choroidal vascular disease underwent vitrectomy. Etiologies included vitreous hemorrhage during anterior segment surgery (22 eyes), blunt trauma (8 eyes), retinal tears with and without retinal detachment (8 eyes), Terson's syndrome (2 eyes), avulsed retinal vessel (1 eye), and idiopathic cases (8 eyes). The final visual acuity improved in 48 eyes (98%). Follow-up was 6-91 months (mean, 20 months). Of the 49 eyes, 40 eyes (82%) had a best postoperative visual acuity of 20/100 or better, 31 eyes (63%) had visual acuity of 20/40 or better, and 12 eyes (24%) had visual acuity of 20/20. The major complications included intraoperative iatrogenic retinal breaks (5 eyes), postoperative progressive cataract (7 eyes), late retinal detachment (4 eyes) and recurrent vitreous hemorrhage (2 eyes). The major complication associated with later visual loss was progressive cataract.

Adolescent↗
PubMed2006

Comparative evaluation of oral fluorescein angiography using the confocal scanning laser ophthalmoscope and digital fundus camera with intravenous fluorescein angiography using the digital fundus camera.

BACKGROUND: To study the efficacy of oral fluorescein angiography (FA) with confocal scanning laser ophthalmoscope (CSLO). METHODS: Ten patients each of choroidal neovascular membrane, central serous retinopathy, diabetic retinopathy and five normal subjects were evaluated with group 1 - intravenous FA using digital fundus camera (DFC); group 2 - oral FA using DFC; and group 3 - oral FA using CSLO. RESULTS: Third-order branch vessels were identified in 85.7% eyes in group 3 versus 51.4% in group 2 (P = 0.004), image quality was comparable to intravenous FA in 77.1% in group 3 versus 48.5% in group 2 (P = 0.02) and margin delineation was better in 80% eyes in group 3 versus 35% in group 2 (P = 0.01). The foveal avascular zone was clear and intact in 54.2% eyes in group 3 versus 37.1% in group 2 (P = 0.14) and 57.1% in group 1 (P = 0.8). CONCLUSION: Oral FA using CSLO is superior to oral FA using DFC and comparable to intravenous FA using DFC in terms of image quality, branch retinal vessel identification and margin delineation.

Administration, Oral↗
PubMed1979

Acute severe uveitis with retinal vasculitis and retinal detachment.

5 adult patients (7 eyes) with acute severe uveitis with retinal vasculitis and retinal detachment of unknown etiology were studied. Yellowish exudations which appeared in the peripheral fundus rapidly extended posteriorly, and there was a patchy perivasculitis, white sheathing and obliteration of the retinal vessels. The absorption of these yellowish exudations was followed by atrophy of the retina and the choroid. Secondary detachment of the retina then developed, and the visual acuity remained poor in most cases.

Acute Disease↗
PubMed1976

A study of the cumulative effects of repeated exposures to radial accelerations.

After exposure to transverse accelerations of 4-10 g changes in the vascular system of the eye and immunobiological resistance of the body persisted from 5 to 15 days. The data give evidence that the state of retinal vessels is the most informative index of the cumulative effect on the body and its recovery.

17-Hydroxycorticosteroids↗
PubMed2004

Severe retinal degeneration associated with disruption of semaphorin 4A.

PURPOSE: Semaphorin 4A (Sema4A) is a member of the transmembrane class 4 family of semaphorins. It has recently been shown to participate in cell-cell communication in the immune system. High levels of sema4A are also present in brain and eye, but its function in the central nervous system has not been studied. To investigate the function of Sema4A, we generated mice deficient in this transmembrane signaling molecule. METHODS: An embryonic stem (ES) cell clone with a retroviral gene-trap insertion in the sema4A gene was used to generate mice lacking this transmembrane semaphorin. Fundus photography, fluorescein angiography, and electroretinography were used to evaluate retinal anatomy and physiology in mice lacking Sema4A. Electron microscopy and immunohistochemistry with cell-type-specific markers were used to characterize retinal development. In situ hybridization with sema4A-specific riboprobes was used to localize expression of this gene in the developing and adult eye. RESULTS: Fundus photography performed at 14 weeks of age revealed severe retinal degeneration, attenuated retinal vessels, and depigmentation in mice lacking Sema4A. At this age, the outer nuclear layer was reduced to a single row of photoreceptor cells, and the outer plexiform layer was thin and disorganized. Disruption of Sema4A also compromised the physiological function of both rod and cone photoreceptors. Developmental studies in Sema4A-deficient mice revealed abnormal morphology of photoreceptor outer segments during the time at which they establish contacts with apical microvilli of the retinal pigment epithelium (RPE). Sema4A is expressed in the inner retina and RPE during the time at which photoreceptor outer segments elongate. CONCLUSIONS: These findings identify a previously unknown function of Sema4A in the developing visual system and provide a useful model for understanding cell-cell interactions that occur between photoreceptors and the RPE.

Animals↗
PubMed1989

Variations in the severity of retinopathy seen in newborn rats supplemented with oxygen under different conditions of hyperbarism.

The purposes of this experimental study were to evaluate the effects of oxygen supplementation delivered under hyperbaric conditions on the retinas of newborn rats and to determine the minimum and maximum levels of hyperbarism capable of protecting the retinal vessels from the toxic effects of oxygen without determining lethal effects in this experimental model. A control group of newborn rats were maintained with their mother for the first 12 days of life under room-air conditions. A second group of animals were exposed to a hyperbaric environment (+81 kPa) under normoxic conditions for the first 7 days of life and subsequently returned to normobaric conditions for the next 5 days. Examination of the retinal flat mounts from this latter group of animals revealed essentially normal vascular networks with only a modest degree of vasoconstriction. Two other litters of ratlings, with their mothers, were given supplemental oxygen at an FiO2 of 80% under a compression pressure of +101.25 kPa. In this group of animals, death of both of the mother rats from pulmonary edema occurred on the first day of treatment, and, in spite of immediate mother substitution, the newborn rats succumbed to the same complication. Five other groups, each containing two litters of newborn rats with their mothers, were exposed to FiO2s of 80% at hyperbaric levels ranging from +20.25- to +81.0 kPa for the first 7 days of life. On the eighth day, the FiO2s were reduced to 21%. After 5 days of room-air recovery, the animals were killed.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1988

Retinopathy of prematurity.

Increasing numbers of immature infants are surviving with incompletely developed retinal vessels at risk for ROP. Since adverse perinatal events seem closely associated with the more severe forms of the disorder, neonatologists may be able to contribute most to the reduction of vision loss if they can optimize the neonatal course of these infants. However, to date, no particular intervention has been proven to be efficacious in preventing ROP. On the other hand, cryotherapy has been found effective in stopping the progress of severe ROP to retinal detachments about half the time. This places a responsibility on the neonatologist and ophthalmologist to assure that each at-risk infant is examined by 4-6 weeks of age to enable the prompt application of cryotherapy if severe ROP develops. This is presently the infant's best chance of retaining useful vision, and appropriate nursery policies should be developed to ensure its availability. Additional research is needed to understand the control of regression vs progression in ROP and to explore potential means of preventing the disease altogether.

Birth Weight↗
PubMed1995

Retinal vasodilation and hyperglycaemia in diabetic children and adolescents.

Retinal vessel diameters of 45 diabetic children and adolescents with diabetes were measured on black-and-white fundus photographs (negatives) using digital image analyses technique and microdensitometry as well as with direct micrometry. The changes in vessel diameters in two sets of photographs taken at an interval of 2.4 +/- 0.3 years were compared with glycated haemoglobin level, retinopathy status and various other parameters. During the follow-up period both arterial and venous diameters increased significantly (p = 0.0436 and p = 0.0001, respectively), but the changes in individual vessels and between patients differed markedly. The superior temporal vein dilated more than the inferior temporal vein. The average increase in venous calibre was related to the glycated haemoglobin level on the date of the second examination (p = 0.0492). Signs of early retinopathy developed more often in the eyes with venous dilation (6 of 18 eyes) than in those without (3 of 24 eyes), but the difference did not reach statistical significance. The results indicate that retinal vasodilation is associated with chronically elevated blood glucose level in diabetic children, and may precede development of other signs of retinopathy.

Adolescent↗