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At least 145 records · Page 8Linked to original sources
PubMed2000

[Extra-ocular etiologic factors in retinal vein occlusion. Retrospective study of 24 patients].

PURPOSE: Retinal vein occlusion has several causes. Cardiovascular risk factors, particularly systemic hypertension; as well as thrombophilia appear to be involved in the development of retinal vein occlusion. METHODS: In a retrospective study we analyzed these factors in 24 patients, admitted for retinal vein occlusion and isovolaemic hemodilution in an internal medicine unit. RESULTS: In patients over 50 years of age, cardiovascular risk factors predominate; while in patients under 50, one patient out of two has biological features indicating a risk for thrombosis. CONCLUSION: Serological abnormalities could be involved in the physiopathology of retinal vein occlusion in young patients.

Adult↗
PubMed1998

Formation of retinochoroidal collaterals in central retinal vein occlusion.

PURPOSE: To demonstrate the drainage routes that compensate the venous congestion in central retinal vein occlusion. METHODS: Indocyanine green angiography was performed in 13 eyes of 13 patients with central retinal vein occlusion at the involutional stage using a scanning laser ophthalmoscope. The interval between onset of central retinal vein occlusion and indocyanine green angiography ranged from 1.0 to 9.3 years (mean, 3.6 years). Panoramic indocyanine green angiograms that covered the entire choroidal vasculature were produced by composing regional angiograms. RESULTS: Retinochoroidal collateral routes were found in 10 eyes that had papillary vascular loops. They were not observed in three eyes that did not have the vascular loops. Papillary vascular loops served as the collaterals to connect retinal veins and choroidal veins. The blood in the retinal veins was drained through the papillary vascular loops into the choroidal veins. These choroidal veins were selectively dilated and acted as drainage routes to the vortex veins. Nasal vortex veins served as extraocular exits of the drainage routes in all 10 eyes, and temporal vortex veins served as extraocular exits of the drainage routes in three of the 10 eyes. CONCLUSIONS: In central retinal vein occlusion with papillary loops, blood in the retinal veins ultimately drained into the vortex veins through the retinochoroidal collaterals.

Aged↗
PubMed1998

Thrombin-antithrombin III complex in acute retinal vein occlusion.

PURPOSE: To determine whether quantitative differences in systemic hypercoagulable state could be identified among patients with retinal vein occlusion at various sites of occlusion. METHODS: The value of thrombin-antithrombin III complex was determined in 57 patients with retinal vein occlusion within 1 month after the subjective onset of retinal vein occlusion and in 15 age-matched normal controls. RESULTS: Levels of log thrombin-antithrombin III complex were significantly higher in the patients with proximal retinal vein occlusion in which the occlusion site is at the optic disc (mean +/- SD, 0.493 +/- 0.389) than in those with distal retinal vein occlusion in which the occlusion site is away from the optic disc (0.312 +/- 0.150, P = .025) and in the normal controls (0.294 +/- 0.151, P = .020). There was no significant difference between the distal retinal vein occlusion and the normal controls (P = .720). More patients with proximal retinal vein occlusion showed elevated thrombin-antithrombin III complex values more than 3.9 ng/ml than those with distal retinal vein occlusion (8/29 vs 1/28, P = .025). Of nine patients showing an initial value of thrombin-antithrombin III complex of more than 3.9 ng/ml, repeated measurements were obtained in eight patients, who showed reduced value of thrombin-antithrombin III complex in the normal range in several months. CONCLUSIONS: A systemic hypercoagulable state, which could be demonstrated with the elevation of thrombin-antithrombin III complex value, may contribute more to the development of retinal vein occlusion with thrombus at or near the trunk of the central retinal vein than those with thrombus at branch veins away from the optic disc in the retina.

Acute Disease↗
PubMed1999

[Quantification of functional retinal damage in branch retinal vein thromboses].

PURPOSE: Branch retinal vein occlusion (BRVO) induces variable functional deficits depending on the grade of vascular occlusion and its localisation. Theses deficiences are not easily defined by visual acuity measurements. However, microperimetry offers topical mapping of retinal function, allowing precise documentation of the intensity and dimension of retinal functional loss in BRVO. METHODS: Retinal sensitivity was examined using a Rodenstock Scanning Laser Ophthalmoscope (SLO). A standardized grading system of stimuli ranging from 0 to 32 dB was used to document the retinal threshold in three different areas: regions presenting vascular occlusion, the collateral edematous zone and adjacent areas with intact perfusion. Absolute and relative scotomas as well as the fixation behavior were studied. RESULTS: Forty-two patients with isolated BRVO within the vascular arcades were examined with microperimetry and angiography. At initial presentation with BRVO the retinal sensitivity in the area of occlusion on average diminished to 4.1 dB. In the collateral edematous zone retinal threshold was reduced to 21.5 dB; area with intact perfusion demonstrated a threshold of 23.2 dB. Within the occluded area itself defects of significantly differing intensity were found which only partially correlated with the angiographic evidence. Intense scotomas (0 dB) were observed in 59% of the eyes examined: angiographically nonperfused areas or extended intraretinal hemorrhage were present. Relative scotomas (12.1 dB) were seen in 19.1% and minimal, non-significant defects (19.5 dB) were documented in 21.4% of the BRVO. The level of angiographically documented leakage did not correlate with the functional deficits present in these two groups. Measurements performed after 6-8 weeks revealed noticeable spontaneous recovery of retinal sensitivity, unless an additional progressive closure occurred. The average functional improvement in the area of leakage found after laser therapy was less than the results shown in spontaneous resolution of edema. CONCLUSIONS: BRVO may lead to significant reductions of central and paracentral retinal function. Angiographically observed leakage is not always directly correlated to the magnitude of retinal sensitivity loss. As spontenous remission is frequent in one group and intact retinal function can be shown in areas of angiographic leakage, therapeutic interventions, e.g., laser treatment, should be carefully considered. Scanning laser ophthalmoscopy provides additional information for precise evaluation and follow-up of the retinal damage in BRVO.

Adult↗
PubMed1999

Protein C, protein S and antithrombin III deficiencies in retinal vein occlusion.

PURPOSE: The role of decreased levels of protein C, protein S and antithrombin III were investigated in patients with branch and central retinal vein occlusion. METHODS: Forty-five patients with retinal vein occlusion and 20 healthy subjects as a control group was studied. Fourteen patients (31%) had central retinal vein occlusion and 31 (69%) had branch retinal vein occlusion. The concentrations of protein C, protein S and antithrombin III were measured. RESULTS: Plasma levels of protein C, protein S and antithrombin III were not reduced in the control group. Six of the 14 central retinal vein occlusion cases and 3 of the 31 retinal branch vein occlusion cases had decreased levels of protein C. One of the 14 central retinal vein occlusion cases and 1 of the 31 retinal branch vein occlusion cases had decreased levels of protein S. Antithrombin III was reduced in 1 patient of the 31 retinal branch vein occlusions. We found statistically significant differences for number of cases with protein C deficiency between the central retinal vein occlusion cases and the branch retinal vein occlusion cases (p<0.05). CONCLUSION: Deficiency of anticoagulant proteins, especially protein C, may play a role in the etiology of retinal vein occlusion. Measurement of these parameters may be useful in preventing venous thrombosis elsewhere in the body.

Biomarkers↗
PubMed1982

Ocular neovascularization with retinal vascular occlusion. I. Association with experimental retinal vein occlusion.

Experimental occlusion of both major temporal retinal veins simultaneously (in six eyes of cynomolgus monkeys) and of the central retinal vein (in one rhesus monkey) produced a fall in intraocular pressure (hypotensive effect) and neovascularization (NV) of the iris and, less frequently, of the optic disc (vasogenic effect). The retinal changes (severity and extent of retinopathy, retinal capillary leakage, and onset and extent of retinal capillary obliteration) were correlated with the pattern of ocular NV and hypotony. No direct correlation was seen between the retinal capillary obliteration and the hypotensive or vasogenic effect. However, a correlation was found between the retinal vascular leakage and the development of ocular NV and hypotony. The pathogeneses of ocular NV and hypotony in retinal vein occlusion are discussed in light of the findings of this study.

Animals↗
PubMed1997

Significance of refractive status in branch retinal vein occlusion. A case-control study.

PURPOSE: To evaluate the significance of refractive error in cases of branch retinal vein occlusion. METHODS: Of 354 patients with branch retinal vein occlusion who attended our clinic between 1989 and 1995, 75 patients with unilateral branch retinal vein occlusion were compared with an equal number of matched controls with similar inclusion and exclusion criteria. The spherical equivalents of the refractive errors of patients in both groups were compared using the chi-square test, student's t test, and multivariate logistic regression. RESULTS: Hypermetropia was present in 53 patients with branch retinal vein occlusion (70.7%) and in 33 control patients (44.0%; P = 0.0001). Myopia was present in 11 patients with branch retinal vein occlusion (14.7%) and in 30 controls (40.0%; P = 0.0005). Emmetropia was present in 11 patients with branch retinal vein occlusion (14.7%) and in 12 controls (16.0%; P = 0.820). The odds ratio of developing branch retinal vein occlusion among patients with hypermetropia was 3.42 (95% Confidence Interval [CI], 1.62-7.2; P = 0.001) when compared with patients with no hypermetropia and 5.3 (95% CI, 2.1-13.3; P = 0.0003) when compared with patients with myopia alone. CONCLUSION: Hypermetropia is significantly more common in patients with branch retinal vein occlusion than in the general population, whereas myopia is significantly less common in these patients.

Aged↗
PubMed1984

Intraocular pressure in retinal vein occlusion.

The intraocular pressure of 59 patients with retinal vein occlusion was studied. Central retinal vein occlusion (CVO) was diagnosed in 24 patients and branch retinal vein occlusion (BVO) was diagnosed in the rest. The intraocular pressure of a sex and age matched group of controls was also studied for comparison. The intraocular pressure in the CVO group were significantly different from those of the matched controls (p less than 0.001). A statistically significant difference of a lesser degree (p less than 0.05) was also found in a comparison of the intraocular pressures of the BVO group with those of their sex and age matched group of controls. These findings may indicate the possible role of increased intraocular pressure in the pathogenesis of CVO and BVO.

Constriction, Pathologic↗
PubMed1993

A comparative study of branch retinal vein occlusion and central vein occlusion amongst Malaysian patients.

A retrospective study of 95 patients with retinal vein occlusion was carried out to determine the clinical presentation and pattern of distribution in the local Malaysian population. There was no significant difference found in its distribution with regards to sex. In comparing branch retinal vein occlusion with central retinal vein occlusion, no significant differences were found in its racial distribution. Branch retinal vein occlusion occurred more commonly among the older patients whereas the converse is true for central retinal vein occlusion. Reduced vision represents the commonest mode of presentation. Hypertension, diabetes mellitus, hyperlipidaemia and haematological disorders are important associated systemic conditions.

Adult↗
PubMed1990

Anatomy of arteriovenous crossings in branch retinal vein occlusion.

We studied the photographic records of 292 eyes, including 103 eyes with branch retinal vein occlusion, 90 fellow eyes, and 99 control eyes without branch retinal vein occlusion. All arteriovenous crossings within three disk diameters of the optic disk, including the crossings at the sites of branch retinal vein occlusions, were studied. The relative positions of the crossing artery and vein could be determined at 1,939 crossings in all eyes. Crossings at which a vein crossed over an artery were a common finding (22.3% to 33.0% of crossings), but were rare at the crossings where branch retinal vein occlusions were found (2.4%). A greater proportion of arterial overcrossings was found in eyes with branch retinal vein occlusions (77.7%) compared to fellow eyes (70.6%) or control eyes (67.0%). Our data indicate that arterial overcrossings are at relatively higher risk of branch retinal vein occlusion than venous overcrossings, and that the risk of branch vein occlusion in an eye is proportional to the number of arterial overcrossings in the eye.

Adult↗
PubMed1994

Color Doppler imaging of arterial blood flow in central retinal vein occlusion.

PURPOSE: The hemodynamics of the retrobulbar arterial circulation of patients with central retinal vein occlusion were evaluated in order to better understand the pathophysiology of this disease. METHODS: Color Doppler imaging was used to measure the peak systolic velocity and vascular resistance (pulsatility index) in the retrobulbar arteries of involved eyes and clinically healthy fellow eyes of patients with central retinal vein occlusion and in the control eyes of age- and sex-matched healthy volunteers. RESULTS: Average peak systolic velocity was significantly lower and average vascular resistance was significantly higher in the central retinal artery of involved eyes of patients with central retinal vein occlusion compared with clinically healthy fellow eyes and compared with control eyes. There also was a trend toward higher vascular resistance in the central retinal artery of clinically healthy fellow eyes of patients with central retinal vein occlusion compared with control eyes. In the ophthalmic arteries and short posterior ciliary arteries, vascular resistance was significantly higher in both the involved eyes and clinically healthy fellow eyes of patients with central retinal vein occlusion compared with control eyes. CONCLUSION: Color Doppler imaging parameters of the central retinal artery circulation were abnormal in eyes with central retinal vein occlusion, suggesting impaired arterial blood flow associated with this disease. The high vascular resistance in the central retinal arteries, ophthalmic arteries, and short posterior ciliary arteries of both involved and clinically healthy fellow eyes of patients with central retinal vein occlusion suggests that diffuse small vessel disease may predate and contribute to the development of central retinal vein occlusion.

Blood Flow Velocity↗
PubMed2005

Role of thrombophilic gene polymorphisms in branch retinal vein occlusion.

OBJECTIVE: Branch retinal vein occlusion (BRVO) is a common cause of severe visual loss. Numerous risk factors, including arterial hypertension, diabetes mellitus, and arteriosclerosis, have been identified. Gene polymorphisms affecting hemostasis may also play a role in the pathogenesis of BRVO. The present study was therefore done to determine the prevalence of genetic polymorphisms in factors implicated in hypercoagulability among patients with BRVO. DESIGN: Retrospective case-control study. PARTICIPANTS: The study cohort consisted of 294 patients with BRVO and 294 control subjects, matched for age and gender. METHODS: Determination of genotypes was done by allele-specific digestion of polymerase chain reaction products, or by 5' exonuclease assay (TaqMan). MAIN OUTCOME PARAMETERS: Genotypes of factor V R506Q (factor V Leiden), prothrombin 20210G>A, fibrinogen beta -455G> A, factor XII (FXII) 46C>T, and ITGA2 807C>T (platelet glycoprotein Ia [GPIa] 807C>T) and ITGB3 L59P (platelet GPIIIa PlA1/PlA2) polymorphisms. RESULTS: Genotype distributions of the investigated gene polymorphisms did not differ significantly between patients and control subjects. In contrast, significantly increased prevalences of arterial hypertension and hypercholesterolemia were found among patients with BRVO. In a logistic regression analysis, the presence of arterial hypertension was associated with an odds ratio (OR) of 2.32 (95% confidence interval [CI], 1.62-3.32), whereas hypercholesterolemia yielded an OR of 2.54 (95% CI, 1.74-3.70) for BRVO. CONCLUSION: Our data indicate that the prevalences of the investigated gene polymorphisms do not differ significantly in patients with BRVO and control subjects. This suggests that these polymorphisms are not major risk factors for BRVO.

Adult↗
PubMed1979

Infrequency of retinal neovascularization following central retinal vein occlusion.

Forty-eight patients with the clinical diagnosis of central retinal vein occlusion and ten surgically enulceated eyes with central retinal vein occlusion documented by histopathologic examination were studied and reviewed. Retinal neovascularization developed in only one of the ten eyes. Rubeosis iridis occurred in 14% (7) of the clinical cases and in all of the histopathologic cases. Ten eyes with neovascular glaucoma, enucleated following central retinal vein occlusion, showed absence of retinal endothelial cells. The absence of retinal capillary endothelial cells is significant in explaining the rare occurrence of retinal neovascularization following central retinal vein occlusion. However, the small number of cases may reflect a biased result. Further studies of more cases over a longer period are required to reach the final conclusion.

Humans↗
PubMed1996

Prognostic factors for retinal vein occlusion: prospective study of 175 cases.

BACKGROUND: The prognosis of retinal vein occlusion is highly unpredictable because nonischemic types may convert into ischemic types within the first months. This study was designed to identify epidemiologic characteristics of the different types of retinal vein occlusion, their visual outcome, and their prognostic factors. METHODS: The authors analyzed prospectively the data from patients who have had retinal vein occlusion with complete medical and biologic examination, including fluorescein angiography, and a 1-year follow-up. RESULTS: One hundred seventy-five retinal vein occlusion eyes consisted of 120 central retinal vein occlusions (CRVO), 7 hemicentral occlusions, and 48 branch occlusions. In initially nonischemic CRVO eyes, retinal ischemia developed in 54%. The study of prognostic factors in the CRVO group showed that older age, male sex, and the number of risk factors (systemic vascular risk factors and glaucoma) were correlated with a poor visual outcome and with the development of retinal ischemia, as well as baseline visual acuity, initial extent of retinal ischemia, and rheologic findings (hematocrit, fibrinogen, and erythrocyte aggregation levels). Logistic regression underlined the prognostic role of sex, the number of risk factors, erythrocyte aggregation, and initial clinical features. Persistent macular edema was shown to be associated with hyperlipidemia and cardiovascular history, and inversely correlated to glaucoma. CONCLUSION: Because clinical characteristics of CRVO may worsen, the authors' results provide a basis to predict visual outcome by taking into account epidemiologic and rheologic findings. A careful follow-up of these patients is recommended.

Adult↗
PubMed1999

Factor V Leiden and prothrombin 20210 A mutations in patients with central and branch retinal vein occlusion.

PURPOSE: The role of factor V Leiden and prothrombin 20210 A mutations has been investigated in patients with central retinal vein occlusion (CRVO), hemispheric retinal vein occlusion (HRVO), and branch retinal vein occlusion (BRVO). METHODS: Factor V Leiden and prothrombin 20210 A were investigated in DNA obtained from the peripheral blood of 52 patients with retinal vein occlusion. Twenty-five of the patients had either CRVO or HRVO, and 27 patients had BRVO. The control groups for factor V Leiden and prothrombin 20210 A were comprised of two separate groups of 81 and 87 healthy individuals, respectively, who had been previously investigated for the mutations at Hacettepe University Department of Hematology. The frequencies of factor V Leiden and prothrombin 20210 A mutations were compared between the patients and the controls using Fisher's exact test. RESULTS: Factor V Leiden mutation was found in 8% of all patients, 4% of the CRVO-HRVO group and 11% of the BRVO patients. Prothrombin 20210 A mutation was not found in any of the patients. Factor V Leiden and prothrombin 20210 A mutations have been previously found in 7% and 2% of the healthy controls, respectively. The differences of frequencies between the patients and the controls were not statistically significant. CONCLUSION: Factor V Leiden and prothrombin 20210 A mutations have not been found to be risk factors in either type of retinal vein occlusion.

Adult↗
PubMed2004

Dilation of the minor arterial circle of the iris preceding rubeosis iridis during retinal vein occlusion.

PURPOSE: To report in four patients with retinal vein occlusion the presence of biomicroscopically visible circulation in the minor arterial circle of the iris, preceding rubeosis iridis in two cases. DESIGN: Retrospective observational case series. METHODS: Four patients with ischemic type of central or hemi-central retinal vein occlusion seen at a single center. RESULTS: Dilation of the minor arterial circle remnants with biomicroscopically visible circulation was observed in four eyes of four adult patients with severe retinal ischemia secondary to retinal vein occlusion and preceded the occurrence of anterior segment neovascularization in two cases. CONCLUSION: In patients with ischemic retinal vein occlusion, the clinical finding of a dilation of the minor arterial circle may indicate the necessity of a closer follow-up to make a timely decision on panretinal photocoagulation.

Aged↗
PubMed1992

Disc edge veins of Kraupa: rare exit anomalies of the retinal vein.

Disc edge veins of Kraupa are anomalies of the retinal venous system in which blood flows from the retina through a single venous trunk at or near the edge of the disc instead of at its centre. We report two examples of patients with these anomalies and illustrate the appearance of the anomalies with fundus photographs and a fluorescein angiogram. In one patient the retinal vein exited the eye through the sclera at the margin of the optic disc; in the other it disappeared into the disc tissue near the disc margin.

Adult↗