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At least 19 recordsLinked to original sources
PubMed1993

Hyperhomocysteinemia in retinal artery and retinal vein occlusion.

In 19 patients who had retinal vein occlusion or retinal artery occlusion before the age of 50 years, the incidence of hyperhomocysteinemia, as observed in heterozygosity for homocystinuria, was studied by the performance of a standardized, oral methionine-loading test. In four of the 19 patients (21%), two with retinal artery occlusion and two with central retinal vein occlusion, the after-load peak levels of homocysteine exceeded the mean level, established in normal control subjects, by more than two standard deviations and were as well within the ranges established in obligate heterozygotes for homocystinuria. Because the frequency of heterozygosity for homocystinuria in the normal population is one in 70 (1.4%) at the most, we conclude that hyperhomocysteinemia predisposes to the development of premature retinal artery and retinal vein occlusion (P < .01; chi 2 test).

Adult↗
PubMed1979

Cilioretinal arteries and retinal arterial occlusion.

A series of 187 cases of retinal artery occlusion was reviewed. 107 of which were central retinal artery occlusions (CRAO). Of the 107 cases, 28 (26%) showed some degree of macular sparing owing to a patent cilioretinalartery. The patients with cilioretinal sparing regained variable degrees of visual acuity, depending on the amount of the pipillomacular bundle supplied by the patent vessel. The patients with CRAO without cilioretinal sparing rarely regained any useful vision. To our knowledge, this is the first large series documenting the degree of visual return in such cases. From this data, guidelines for counseling patients with CRAO with cilioretinal sparing are presented.

Aged↗
PubMed2003

Short posterior ciliary artery, central retinal artery, and choroidal hemodynamics in brimonidine-treated primary open-angle glaucoma patients.

PURPOSE: Malfunction in peripapillary hemodynamics has been suggested to play a major part in the pathogenesis of primary open-angle glaucoma (POAG). The aim of this study was to determine whether topically applied brimonidine can influence blood hemodynamic characteristics associated with the perioptic short posterior ciliary arteries (SPCAs), central retinal artery (CRA), and choroidal vascular system in POAG patients. DESIGN: Randomized clinical trial. In this prospective, institutional, double-masked, vehicle-controlled, randomized clinical trial, the intraocular pressure (IOP) and vascular dynamics of the SPCAs, CRA, and choroidal vascular system were analyzed in both eyes of 17 POAG patients, before and after treatment with 0.2% brimonidine for 4 weeks. RESULTS: Mean IOP reduction was significant (18.7%) following treatment with brimonidine. However, no clear changes were recorded with respect to blood perfusion parameters (peak systolic velocity, end-diastolic velocity, pulsatility, and resistance indices) associated with the SPCAs and CRA or the choroidal ocular pulse amplitude. CONCLUSIONS: Topical treatment of brimonidine to POAG patients causes a significant reduction of IOP, but blood hemodynamic properties associated with the SPCAs, CRA, and choroidal vascular systems appeared unaffected. Topically applied brimonidine, therefore, appears not to constrict or dilate peripapillary blood vessels.

Administration, Topical↗
PubMedDate not supplied

Occlusive thromboaortopathy (Takayasu's disease): cervical arterial stenoses, retinal arterial pressure, retinal microaneurysms and prognosis.

Eighty-one young Japanese patients with occlusive thromboaortopathy (Takayasu's disease) were classed into three groups according to the degree and extent of diameter stenosis in the 4 cervical arterial systems, as determined by serial aortography. Class I was made up of 63 patients with 70% or greater stenosis in less than 3 systems, including 33 patients without systemic hypertension (Class Ia). Class II was made up of 6 patients with 70% or greater stenosis in 3 systems and less than 50% stenosis in the remaining 1, including 5 patients without systemic hypertension (Class IIa). Class III was up of 12 patients with 70% or greater stenosis in 3 systems and 50% or greater stenosis in 1 system. Ophthalmodynamometric systolic pressure in patients in Class III was significantly lower than that in patients in Class IIa (p less than 0.001), but there was no significant difference between patients in Classes Ia and IIa. Microaneurysms and/or arteriovenous anastomoses in the retinal vessels were found in all but one patient in Class III and in only one patient in combined Classes I and II. These results indicate that each of the ophthalmodynamometric values and fundoscopic findings are very helpful in identifying the markedly severe occlusive lesions (Class III) of the 4 cervical arterial systems. In this chronic disease, however, angiography is most useful for evaluation of these severe lesions, to monitor progression from Classes I and II to Class III, in which the prognosis is rather poor.

Adult↗
PubMed2004

Central retinal artery occlusion. Retinal survival time.

PURPOSE: To investigate the retinal survival time following central retinal artery occlusion (CRAO). METHODS: In 38 elderly, atherosclerotic and hypertensive rhesus monkeys, transient CRAO (varying from 97 to 240 min) was produced by temporarily clamping the CRA at its site of entry into the optic nerve. Stereoscopic color fundus photography, fluorescein fundus angiography, electroretinography (ERG), and visual evoked potential (VEP) recording were performed before and during CRA clamping, after unclamping, and serially thereafter. After unclamping of the CRA, the animals were followed for variable lengths of time (median duration 8.14 weeks). Finally, the eyes and optic nerves were examined histologically. The data on ERG changes were analyzed in the following four time frames: (1) baseline before CRA clamping, (2) during CRA clamping, (3) immediately after unclamping, and (4) at the end of follow-up. Duration of CRAO was divided into four groups: 97, 105-120, 150-165, and > or = 180 min. RESULTS: A 'negative ERG' appeared during CRA clamping. With removal of the CRA clamp, there was b-wave recovery, with differential rates of recovery of ERG-eyes with shorter CRAO recovered sooner than those with longer occlusion. On removal of clamp, recovery was seen in scotopic 24 dB b-wave, photopic 0 dB single flash b-wave and 30 Hz flicker, with the b/a ratio of the combined rod and cone response and selective rod response showing statistically significant differences amongst the shorter and longer periods of CRAO. A delayed normalization of the depressed b/a ratio immediately after CRA reperfusion may indicate high-grade ischemic damage. At the final follow-up test session, no clear-cut derangement of any ERG parameter was seen for any group, with subtotal b-wave amplitude recovery for all groups. Longer CRAO produced incomplete VEP recovery. On histology, in the macular retina, eyes with CRAO for 97 min showed practically no damage, but duration of CRAO was found to be significantly associated with the amount of damage in the ganglion cell layer (p = 0.009) and inner nuclear layer (p = 0.017). Outer nuclear and plexiform layers and photoreceptors showed no damage at all with CRAO. There was no significant association of the ERG measures and histologic changes with any of the residual retinal circulation variables. CONCLUSIONS: Our electrophysiologic, histopathologic and morphometric studies showed that the retina of old, atherosclerotic, hypertensive rhesus monkeys suffers no detectable damage with CRAO of 97 min but above that level, the longer the CRAO, the more extensive the irreversible damage. The study suggests that CRAO lasting for about 240 min results in massive irreversible retinal damage.

Animals↗
PubMed2002

[Central retinal artery occlusion or branch retinal artery occlusion in the young associated with high lipoprotein (a) levels].

INTRODUCTION: High plasma lipoprotein (a) concentration is an independent risk factor for atherosclerosis and thrombosis. PATIENTS: We present the cases of two young women, one with central retinal artery occlusion and the other with branch retinal artery occlusion. Case 1: A 32-year-old woman was seen in our clinic complaining of a sudden decrease in visual acuity to 1/50 with a central visual field defect in the right eye. The fundus examination revealed an occlusion of the central retinal artery, which was confirmed by fluorescein fundus angiography. Thorough systemic evaluation showed no signs of cardiovascular disease, no coagulation abnormalities, and no clinical or biological evidence of a systemic disorder. On the other hand, hypercholesterolemia and elevated levels of lipoprotein (a) were detected. Case 2: A 35-year-old woman consulted complaining of a visual field loss in the left eye without reduction of visual acuity. Fundus examination and angiography showed the occlusion of the temporal-superior branch artery. A detailed systemic work-up revealed a pseudo-bicuspid aortic valve and high lipoprotein (a) levels. CONCLUSION: These two cases emphasize the importance of a thorough systemic evaluation of young adults with a retinal artery occlusion. High plasma lipoprotein (a) concentration is a risk factor which should not be neglected.

Adult↗
PubMed2004

Accelerated reperfusion of poorly perfused retinal areas in central retinal artery occlusion and branch retinal artery occlusion after a short treatment with enhanced external counterpulsation.

BACKGROUND: To date, no satisfactory therapy has become available for patients with acute central retinal artery occlusion (CRAO) or branch retinal artery occlusion (BRAO). Enhanced external counterpulsation (EECP) is a new noninvasive procedure that increases perfusion of inner organs. In the current study, the authors measured the impact of EECP on reperfusion in ischemic retinal tissue. METHODS: In a prospective, randomized study, 20 patients with CRAO or BRAO were included. Ten patients were given hemodilution therapy and 2 hours of EECP, and 10 patients were given regular hemodilution therapy only. Quantification of changes in retinal perfusion was carried out by means of scanning laser Doppler flowmetry (in arbitrary units). RESULTS: Enhanced external counterpulsation caused no observable adverse events. A significant increase in perfusion occurred immediately after EECP in the ischemic retinal areas (57 +/- 19 arbitrary units versus 99 +/- 14 arbitrary units). In contrast, no change was measured in the group not treated with EECP (83 +/- 19 arbitrary units versus 89 +/- 44 arbitrary units). Forty-eight hours later, a significant increase in perfusion could be shown in the ischemic retina of both groups, and no significant difference of perfusion was found between the two groups any longer. CONCLUSION: The current study suggests that EECP could be a clinically useful and safe procedure in patients with CRAO or BRAO to accelerate recovery of perfusion in ischemic retinal areas.

Aged↗
PubMed2006

Evaluation of blood flow in the ophthalmic artery and central retinal artery in children with retinopathy of prematurity.

PURPOSE: To evaluate blood flow parameters in the ophthalmic artery and central retinal artery in children with retinopathy of prematurity (ROP). MATERIAL AND METHODS: The study comprised 57 premature children born between 24 and 33 weeks of gestation, with birth weight from 600 g to 1660 g, including 42 preterm children with retinopathy in stage 1, 2, 3 and 3 "plus" and 15 preterm children without retinopathy. Color Doppler ultrasonography (USG-CD) was used to measure in the studied vessels maximal systolic velocity (Vmax), end-diastolic velocity (Vmin) and resistance index (RI). RESULTS: Statistically significantly (p < 0.05) higher values of Vmax were seen in the ophthalmic artery and central retinal artery in preterm children with retinopathy in stage 2 and 3, as compared with other children. In preterms with dilation and tortuosity of posterior blood vessels in stage 3 "plus" ROP Vmax in both studied vessels was lower and was comparable to that in stage 1 ROP and in children without retinopathy. RI in the ophthalmic artery in children with ROP in stage 2 and 3 was statistically significantly higher (p < 0.05) from its values seen in other groups, and for the central retinal artery RI did not differ statistically significantly. CONCLUSIONS: The conducted USG-CD measurements revealed that in children with retinopathy of prematurity haemodynamic parameters of blood flow in the ophthalmic artery and central retinal artery differ in relation to disease stage of advancement, and in relation to the status of blood vessels in the eye fundus. The clinical implications of these results, however, need to be confirmed in long term studies, in order to determine the sensitivity, specificity and repeatability of this method, as well as to establish the diagnostic standards.

Analysis of Variance↗
PubMed1998

[Obstructions of the retinal artery branches--the clinical and therapeutic aspects].

The purpose of the study is the evaluation of the therapeutical results in arterial retinal branches obstructions, according their etiology and clinical features. The study includes 30 patients with arterial retinal branch obstructions, hospitalized in the Ophthalmological Department from Cluj, between 1989-1996. The temporal branches have been significantly more frequently affected (73.33%), as compared to the nasal ones (6.66%). We noticed no difference in visual acuity's recovery according the precocity of the therapy. Visual acuity's recovery after the arterial retinal branches obstructions is under the simultaneous influence of a group of factors. In this context, the most important ones are: the etiopathogenetic mechanism and the degree of the arterial obstruction. Under these circumstances, an important consideration has to be given to the prophylactic component of the treatment.

Adult↗
PubMed2005

Intra-arterial thrombolysis for retinal artery occlusion: the Calgary experience.

INTRODUCTION: Retinal artery occlusion represents a medical emergency with poor prognosis for visual recovery. Spontaneous improvement is estimated to occur in less than 15% of central retinal artery occlusion (CRAO) cases and conventional treatments have provided only limited benefit. Intra-arterial thrombolysis has been reported as a potentially efficacious and safe treatment. METHODS: We performed a retrospective chart review of all retinal artery occlusion cases treated with intra-arterial recombinant tissue-type plasminogen activator (rtPA) from January 1998 to May 2004. Patients received Goldmann perimetry visual field testing at a variable interval following the procedure (2 days-2.5 years). Visual acuity (VA) was re-assessed in May 2004. RESULTS: Eight cases (59-77 years) were treated for CRAO, 6-18 hours post-onset with intra-arterial rtPA (10-20 mg over 15-60 minutes); one case of branch occlusion (BRAO) was treated with 30 mg rtPA over 75 minutes, 12 hours post-onset. Among the six patients with CRAO assessed in clinic, three experienced improvement in VA by two or more gradations (Snellen lines); three improved by one gradation. However, none achieved a final VA better than 20/300. The case of branch occlusion improved to a VA of 20/20. All patients had residual monocular field defects. CONCLUSIONS: Our findings reveal a limited benefit for intra-arterial tPA compared to the rate of spontaneous improvement and conventional forms of therapy for retinal artery occlusion.

Adult↗
PubMed1983

[Arterial retinal circulatory disorders: an urgent indication for Doppler sonographic study of the carotid flow system].

Nineteen subjects with retinal strokes of different degrees of severity (amaurosis fugax, occlusion of individual retinal arteries or of the central retinal artery) were examined by continuous-wave Doppler sonography. Evaluation of periorbital Doppler flow and direct examination of the major neck vessels were performed. Twelve subjects presented with homolateral arteriosclerotic lesions at the carotid bifurcation. The ultrasonographic findings were confirmed by carotid arteriography. High-grade stenosis or occlusion of the internal carotid artery were found in approximately 50% of the patients; the remainder turned out to have low-grade stenoses or nonstenosing plaques. These findings emphasize the role of emboli from the major neck arteries in the pathogenesis of retinal and cerebral insults. Hemodynamic effects seem to be of minor significance. Continuous-wave Doppler sonography is a completely non invasive, but nevertheless reliable method for the detection of clinically relevant carotid lesions. Especially patients suffering from retinal insults should be examined by Doppler sonography, since they are at high risk for further cerebral stroke.

Aged↗
PubMed1990

Combined branch retinal artery and central retinal vein obstruction.

We observed seven patients with the unusual combination of a central retinal vein obstruction in conjunction with a simultaneous branch retinal artery obstruction. The patients presented with sectoral retinal whitening, as well as diffuse peripapillary and superficial retinal hemorrhages. In five of the seven patients, the retinal hemorrhages appeared most florid in the territory of the obstructed arteriole, resulting initially in the consideration that these cases represented a combined branch retinal artery and branch retinal vein obstruction. In all cases, however, the presence of dilated, tortuous veins with diffuse retinal hemorrhages, in addition to generalized delay in arteriovenous transit on fluorescein angiography, localized the venous blockage to the central retinal vein. No intra-arterial retinal emboli were visualized. Initially, five of the seven patients suffered markedly diminished visual function; although visual acuity returned to near normal in all but two patients. In the two patients with non-resolving, markedly impaired visual acuity, neovascularization of the iris complicated the clinical course. Both of these patients were treated with panretinal photocoagulation, with resolution of the iris neovascularization. These seven patients highlight another variation of combined arterial and venous retinal vascular disease.

Adult↗
PubMedDate not supplied

The role of a second isolated retinal artery in branch retinal vein obstruction.

PURPOSE: To evaluate the prevalence of a second isolated retinal artery in eyes with and without branch retinal vein obstruction (BRVO). METHODS: A retrospective study of the color photographs and fluorescein angiograms of 100 patients with unilateral BRVO (64 superotemporal and 34 inferotemporal) and a control group of 33 patients (66 eyes) with different ailments was made. The prevalence of a second isolated retinal artery, which coursed closer to the macular region, in BRVO eyes, fellow eyes and eyes of the control group was evaluated. The types and sites of arteriovenous crossings were also recorded for comparison. RESULTS: The eyes with BRVO, which involved the superotemporal quadrant, had significantly larger numbers of arteriovenous crossings than did fellow eyes (p = 0.02) and control eyes (p = 0.001). In the superotemporal quadrant, a significantly higher percentage (35 of 66, 53%) of the control eyes had a second isolated retinal artery than did BRVO eyes (16 of 64 cases, 25%, p = 0.001). CONCLUSIONS: The second isolated retinal artery, which has not been previously mentioned in the literature, may lower the chance of arteriovenous crossings and play a protective role in BRVO.

Adult↗
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↗