Intra-arterial fibrinolytic therapy in central retinal artery occlusion

Visual outcomes of central retinal artery occlusion: Exploring treatment strategies beyond the conventional time window

BACKGROUNDS/AIMS

Central retinal artery occlusion (CRAO) is a vision-devastating emergency. However, widely-acknowledged treatment consensus is lacking and prehospital delays commonly occur. Hence, we aimed to investigate the visual outcomes of conservative treatments (CT), local intra-arterial fibrinolysis (LIF) and hyperbaric oxygen (HBO) therapy for non-arteritic CRAO (NA-CRAO) patients beyond the conventional time window.

METHODS

This retrospective comparative study included 99 NA-CRAO patients followed up for over 6 months. The subjects were divided into three groups: the CT (50 patients), LIF (10 patients) and HBO group (39 patients). The primary endpoint was the best-corrected visual acuity (BCVA) change at 6 months compared to baseline. The secondary endpoint was the improvement in BCVA at 1 year and final visits.

RESULTS

No heterogeneity regarding demographics was identified. However, the HBO group had a more extended time-to-treatment period (median 6.0 days) and more advanced-stage CRAO cases (41 % stage III) than the CT (median 4.0 days, 14 % stage III) and LIF (median 0.6 days, 20 % stage III) groups. Despite this, the HBO group exhibited a significantly greater BCVA and a higher proportion of patients achieving significant vision improvement than those in the CT group at 6-, 12-month and final exams (51.3 % vs. 24.0 %, P < 0.05). The LIF appeared to improve outcomes more than CT over time without significance.

CONCLUSION

Our study provided a concurrent comparison across 3 approaches and demonstrated that HBO therapy beyond the time window remained more effective in improving vision than CT alone for NA-CRAO patients, which had not been proposed by prior studies.

Retina-Brain Homology: The Correlation Between Ophthalmic or Retinal Artery Occlusion and Ischemic Stroke

The retina's similar structure and function to the brain make it a unique visual "window" for studying cerebral disorders. Ophthalmic artery occlusion (OAO) or retinal artery occlusion (RAO) is a severe ophthalmic emergency that significantly affects visual acuity. Studies have demonstrated that patients with OAO or RAO face a notably higher risk of future acute ischemic stroke (AIS). However, ophthalmologists often overlook multidisciplinary approach involving the neurologist, to evaluate the risk of AIS and devise clinical treatment strategies for patients with OAO or RAO. Unlike the successful use of thrombolysis in AIS, the application of thrombolysis for OAO or RAO remains limited and controversial due to insufficient reliable evidence. In this review, we aim to summarize the anatomical and functional connections between the retina and the brain, and the clinical connection between OAO or RAO and AIS, compare and review recent advances in the effectiveness and safety of intravenous and intra-arterial thrombolysis therapy in patients with OAO or RAO, and discuss future research directions for OAO or RAO. Our goal is to advance the development of multidisciplinary diagnosis and treatment strategies for the disease, as well as to establish expedited pathways or thrombolysis guidelines for vascular intervention.

Improved visual outcomes of central retinal artery occlusion with local intra-arterial fibrinolysis beyond the conventional time window

Local intra-arterial fibrinolysis (LIF) is a promising therapeutic option for CRAO. However, the narrow time window of 6 h has greatly limited the application of LIF. In this study, we explored the efficacy of LIF beyond the conventional time windows and compared the result with conservative therapy. This prospective study included 179 CRAO patients with baseline visual acuity (VA) ≤ 20/400 treated at Renmin Hospital of Wuhan University. The mean time from vision loss to presentation was 5.5 days. 58 patients received conventional standard therapy (CST) alone.121 patients underwent LIF. Main outcome was VA improvement ≥ 0.3 logMAR. Secondary outcome was a favorable VA outcome of 20/200 or better. Logistic regressions were performed to identify predictors of visual improvement. 43% patients in the LIF group experienced VA improvement versus 19% with CST (P = 0.002). LIF was associated with 4.0-fold higher likelihood of visual improvement compared to CST (P = 0.001). Poor baseline VA (light perception or no light perception) and shortened prothrombin time (PT) were associated with greater chance of visual improvement with LIF. However, LIF showed no significant advantage over CST for favorable VA outcomes. No major complications occurred. LIF beyond the therapeutic time window improved vision in functionally blind CRAO patients and showed better efficacy when compared with CST. PT may be a potential predictor of visual outcome after LIF. Our findings could complement existing time-based treatment guidelines and potentially allow for personalized decisions on the use of LIF beyond time windows.

Interventions for acute non-arteritic central retinal artery occlusion

BACKGROUND

Acute non-arteritic central retinal artery occlusion (CRAO) occurs as a sudden interruption of the blood supply to the retina and typically results in severe loss of vision in the affected eye. Although many therapeutic interventions have been proposed, there is no generally agreed upon treatment regimen.

OBJECTIVES

To assess the effects of treatments for acute non-arteritic CRAO.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (which contains the Cochrane Eyes and Vision Trials Register) (2022, Issue 2); Ovid MEDLINE; Embase.com; PubMed; Latin American and Caribbean Health Sciences Literature Database (LILACS); ClinicalTrials.gov; and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP). We did not use any date or language restrictions in the electronic search for trials. We last searched the electronic databases on 15 February 2022.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) comparing any interventions with another treatment in participants with acute non-arteritic CRAO in one or both eyes.  DATA COLLECTION AND ANALYSIS: We used standard Cochrane methodology and graded the certainty of the body of evidence for primary (mean change in best-corrected visual acuity [BCVA]) and secondary (quality of life and adverse events) outcomes using the GRADE classification.

MAIN RESULTS

We included six RCTs with 223 total participants with acute non-arteritic CRAO; the studies ranged in size from 10 to 84 participants. The included studies varied geographically: one in Australia, one in Austria and Germany, two in China, one in Germany, and one in Italy. We were unable to conduct any meta-analyses due to study heterogeneity. None of the included studies compared the same pair of interventions: 1) tissue plasminogen activator (t-PA) versus intravenous saline; 2) t-PA versus isovolemic hemodilution, eyeball massage, intraocular pressure reduction, and anticoagulation; 3) nitroglycerin, methazolamide, mecobalamin tablets, vitamin B1 and B12 injections, puerarin and compound anisodine (also known as 654-2) along with oxygen inhalation, eyeball massage, tube expansion, and anticoagulation compared with and without intravenous recombinant tissue plasminogen activator (rt-PA); 4) transcorneal electrical stimulation (TES) with 0 mA versus with 66% of the participant's individual electrical phosphene threshold (EPT) at 20 Hz (66%) versus with 150% of the participant's individual EPT (150%) at 20 Hz; 5) ophthalmic artery branch retrograde thrombolysis versus superselective ophthalmic artery thrombolysis; and 6) pentoxifylline versus placebo. There was no evidence of an important difference in visual acuity between participants treated with t-PA versus intravenous saline (mean difference [MD] at 1 month -0.15 logMAR, 95% confidence interval [CI] -0.48 to 0.18; 1 study, 16 participants; low certainty evidence); t-PA versus isovolemic hemodilution, eyeball massage, intraocular pressure reduction, and anticoagulation (MD at 1 month -0.00 logMAR, 95% CI -0.24 to 0.23; 1 study, 82 participants; low certainty evidence); and TES with 0 mA versus TES with 66% of EPT at 20 Hz versus TES with 150% of EPT at 20 Hz. Participants treated with t-PA experienced higher rates of serious adverse effects. The other three comparisons did not report statistically significant differences. Other studies reported no data on secondary outcomes (quality of life or adverse events).  AUTHORS' CONCLUSIONS: The current research suggests that proposed interventions for acute non-arteritic CRAO may not be better than observation or treatments of any kind such as eyeball massage, oxygen inhalation, tube expansion, and anticoagulation, but the evidence is uncertain. Large, well-designed RCTs are necessary to determine the most effective treatment for acute non-arteritic CRAO.

Efficacy and safety of intra-arterial thrombolysis in patients with central retinal artery occlusion: a systematic review and meta-analysis

PURPOSE

To investigate the efficacy and safety of intra-arterial thrombolysis (IAT) in patients with central retinal artery occlusion (CRAO).

METHODS

PubMed and EMBASE were searched for potentially eligible studies that reported IAT in CRAO patients from inception to Nov 8, 2021. Standard mean difference (SMD) was pooled to compare visual acuity (VA) at baseline with final in IAT patients. The rates and odds ratios (OR) were meta-analyzed to compare VA improvement in IAT with non-IAT patients, stratified to different times from onset to procedure, different definitions of VA improvement, and three CRAO stages. Adverse effects were recorded.

RESULTS

Fifteen studies were included, enrolling 507 CRAO patients who received IAT and 296 CRAO patients who did not. VA was significantly improved from baseline to final VA in IAT patients (SMD [LogMAR] 0.70, 95% CI [0.51, 0.90]). VA improvement rate was higher in IAT patients than that in non-IAT (56% vs 32%, OR 3.55, 95%CI [1.74, 7.24]), with greater OR in IAT within 6 h from onset to procedure (OR 4.60, 95%CI [1.24, 16.99]) than that beyond 6 h (OR 3.36, 95%CI [1.43, 7.85]). The benefit remained consistent when VA improvement was defined as ≥ 3 lines on the Snellen chart (OR 4.68, 95%CI [2.10, 10.41]) and was even greater when CRAO was incomplete. Five patients had a symptomatic intracranial hemorrhage and 21 patients had ischemic stroke or transient ischemic attack after IAT.

CONCLUSIONS

IAT treatment has certain potential in ameliorating VA in CRAO patients, which should be balanced against cerebral complications.

Better late than never: initial experience of intra-arterial pulsed-urokinase-injection as a salvage therapy for refractory sudden sensorineural hearing loss

BACKGROUND AND PURPOSE

Cochlear vascular micro-thrombosis has been hypothesized as one of the pathogenic mechanisms for sudden sensorineural hearing loss (SSNHL) refractory to regular management. This study aimed to evaluate the feasibility and safety of intra-arterial pulsed-injection urokinase (IAPU) as a salvage therapy for SSNHL after the failure of conventional therapy.

METHODS

We retrospectively reviewed our patient database to identify refractory SSNHL patients between November 2017 and July 2020. Study outcomes before and after the IAPU therapy were compared between IAPU and conventional therapy groups.

RESULTS

Sixty-seven moderate-profound SSNHL patients (29 in IAUP group, 38 in control group) were included in this study. Compared to the control group, patients in the IAPU group showed more significant improvement in pure tone average (PTA) (34.2 ± 23.5 vs. 10.7 ± 13.1, p < 0.001) and degree of hearing recovery (total: 20.7% vs. 5.3%, partial: 24.1% vs. 10.5%, mild: 27.6% vs. 13.2% and non: 27.6% vs. 71.1%) 2 weeks after admission. In the IAPU group, a significant improvement of PTA (86.6 ± 11.5 vs. 54.6 ± 20.1 dB, p < 0.005) was observed on the first day after IAPU treatment.

CONCLUSION

In carefully selected SSNHL cases with a highly suspected vascular origin, IAPU is a safe and effective therapy when conventional treatments have failed. Despite the encouraging findings of our work, large studies are needed to better investigate the strengths and limitations of this salvage therapy.

The actual role of thrombolytic treatment in central retinal artery occlusion

OBJECTIVE

The purpose of this study is to determine the application of thrombolytic treatment in central retinal artery occlusion (CRAO), its real benefit, safety and possible indications for treatment.

METHODS

We searched the PubMed, Cochrane and Google Scholar databases delving first into the effectiveness of the traditional treatment for CRAO, and then comparing them with new treatment strategies with intra venous or intra arterial fibrinolysis.

RESULTS

Whereas small retrospective and open-label observational trials support the use of thrombolytic therapy, multicenter randomized trials failed to demonstrate a significant visual improvement with this new strategy. Besides that, a greater risk of life threatening adverse event was observed in patients using thrombolytic treatment.

CONCLUSION

Until well-conducted clinical trials demonstrate a clear benefit of thrombolytic therapy for improving visual acuity and their benefit are weighted against the frequency and severity of adverse events, we could not recommend fibrinolysis for treating CRAO.

Dramatic recovery of vision in patient with acute central retinal artery occlusion treated with local intra-arterial tissue plasminogen activator

Central retinal artery occlusion (CRAO) is a devastating disease resulting in severe visual loss in most cases. It has no proven treatment, and a variety of management options used clinically all have dismal rate of success. We report outcome of treatment with local intra-arterial thrombolysis administered 2.75 hours after devastating visual loss from incomplete CRAO.

Intra-Arterial Thrombolysis for Central Retinal Artery Occlusion

Introduction

Central retinal artery occlusion is an ophthalmic emergency which typically causes acute, painless visual loss. Several conservative treatment options are practiced with little benefit. Thrombolysis as a therapeutic option has gathered interest as well as controversy. This paper aims at reviewing the relevant literature to assess the efficacy and safety of intra-arterial thrombolysis for acute central retinal artery occlusion.

Methods

A review of the literature was conducted. Keywords included “intra-arterial thrombolysis” or “intra-arterial fibrinolysis” in combination with “central retinal artery occlusion” or “CRAO”. A Cochrane Database search was performed for randomised control trials, systematic reviews and meta-analyses using the same keywords.

Results

Twenty-eight studies were identified which included case reports, case series, case-control studies and 1 randomised control trial: the European Assessment Group for Lysis in the Eye Study. Improvement in vision was measured using different methods and at different time points. The findings of these studies generally favour an effect towards intra-arterial thrombolysis however there are many limitations. Additionally, the European Assessment Group for Lysis in the Eye Study showed lack of effect in intra-arterial thrombolysis vs conservative measures.

Conclusion

Current evidence is not sufficient to recommend intra-arterial thrombolysis due to the variability of visual improvement within retrospective studies, heterogeneity in treatment regimens between studies and adverse effects. Intra-arterial thrombolysis may have a role in patients presenting early, particularly if they have monocular vision, after discussion of the risks and benefits. Further high-quality trials assessing the clinical efficacy of intra-arterial thrombolysis may shed more light on this topic.

Central retinal artery occlusion - rethinking retinal survival time

Background

The critical time from onset of complete occlusion of the central retinal artery (CRA) to functionally significant inner retinal infarction represents a window of opportunity for treatment and also has medical-legal implications, particularly when central retinal artery occlusion (CRAO) complicates therapeutic interventions. Here, we review the evidence for time to infarction from complete CRAO and discuss the implications of our findings.

Methods

A Medline search was performed using each of the terms “central retinal artery occlusion”, “retinal infarction”, “retinal ischemia”, and “cherry red spot” from 1970 to the present including articles in French and German. All retrieved references as well as their reference lists were screened for relevance. An Internet search using these terms was also performed to look for additional references.

Results

We find that the experimental evidence showing that inner retinal infarction occurs after 90–240 min of total CRAO, which is the interval generally accepted in the medical literature and practice guidelines, is flawed in important ways. Moreover, the retinal ganglion cells, supplied by the CRA, are part of the central nervous system which undergoes infarction after non-perfusion of 12–15 min or less.

Conclusions

Retinal infarction is most likely to occur after only 12–15 min of complete CRAO. This helps to explain why therapeutic maneuvers for CRAO are often ineffective. Nevertheless, many CRAOs are incomplete and may benefit from therapy after longer intervals. To try to avoid retinal infarcton from inadvertent ocular compression by a headrest during prone anesthesia, the eyes should be checked at intervals of less than 15′.

Intra-Arterial Thrombolysis for Acute Central Retinal Artery Occlusion: A Systematic Review and Meta-Analysis

Background and purpose

Acute central retinal artery occlusion (CRAO) is a serious ophthalmologic emergency that may result in monocular blindness. To date, studies evaluating intra-arterial thrombolysis (IAT) have not shown a definitive clinical benefit. We have conducted a systematic review with a meta-analysis to effectively evaluate this treatment option.

Methods

A systematic literature search was focused on studies containing five or more patients undergoing IAT that included a control group treated with standard therapy. Pooled meta-analysis was performed.

Results

Five retrospective controlled studies and one randomized clinical trial were identified satisfying all inclusion criteria resulting in the analysis of 236 patients treated with IAT and 255 patients treated with ST. A pooled fixed effects analysis resulted in an estimated odds ratio of 2.52, 95% CI (1.69, 3.77) (P < 0.0001) favoring IAT.

Conclusion

IAT is a promising therapeutic option for CRAO with great potential. Further randomized trials are needed to establish a significant benefit and ensure the safety of the intervention.

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.

Conclusion:

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.

Visual Improvement after Intra-Arterial Thrombolysis for Central Retinal Artery Occlusion Does Not Correlate with Time to Treatment

BACKGROUND

Intra-arterial thrombolysis (IAT) for the treatment of acute central retinal artery occlusion (CRAO) has demonstrated variable results for improving visual acuity and remains controversial. Despite limited evidence, time from symptom onset to thrombolysis is believed to be an important factor in predicting visual improvement after IAT.

METHODS

A comprehensive review of the literature was conducted and individual subject level data were extracted from relevant studies. From these, a secondary analysis was performed. Initial and final logarithm of the minimum angle of resolution (logMAR) scores were either abstracted directly from relevant studies or converted from provided Snellen chart scores. Change in logMAR scores was used to determine overall treatment efficacy.

RESULTS

Data on 118 patients undergoing IAT from five studies were evaluated. Median logMAR improvement in visual acuity was -0.400 (p < 0.001). There was no significant association between logMAR change and time to treatment when time (hours) was described as a continuous variable or described categorically [0-4, 4-8, 8-12, 12+ h; or 0-6, 6-12, 12+ h].

CONCLUSION

The visual improvement observed in this series had no relationship to the time from symptom onset to treatment with IAT. This suggests that patients may have the possibility for improvement even with delayed presentation to the neurointerventionalist. Other factors, such as completeness of retinal occlusion, may be more important than time to treatment. Additional studies to determine optimal patient selection criteria for the endovascular treatment of acute CRAO are needed.

Predictors of prognosis and treatment outcome in central retinal artery occlusion: local intra-arterial fibrinolysis vs. conservative treatment

INTRODUCTION

The study analyses patients' risk factors to determine prognostic and predictive factors in patients with acute central retinal artery occlusion (CRAO) treated in the randomized European Assessment Group for Lysis in the Eye (EAGLE) Study with local intra-arterial fibrinolysis (LIF) or conservative standard treatment (CST). These data could improve patient selection for either method.

METHODS

Post hoc statistical analysis of effects of risk factors on overall best corrected visual acuity (BCVA [logarithm of the minimum angle of resolution (logMAR)]) at baseline and month 1 (prognostic effect) and on the difference between outcome of CST and LIF (predictive effect) was conducted.

RESULTS

Seventy two of 84 EAGLE datasets were included. Prognostic effect: Patients with coronary heart disease (CHD) presented worse BCVA at baseline (0.39 logMAR, p = 0.0097). Patients with time from occlusion to treatment <12 h showed a trend to better vision gain at month 1 (-0.23 logMAR, p = 0.086), similarly smoking (-0.24 logMAR, p = 0.077). Predictive effect: Age (<60 years favours LIF -0.54 logMAR; >70 years favours CST 0.28 logMAR; interaction p = 0.070) and CHD (favours CST 0.44 logMAR; interaction p = 0.073) might be predictors of therapeutic outcome. There were no strong effects in multivariate analysis.

CONCLUSION

CHD, time from occlusion to treatment and smoking influence BCVA at baseline and at month 1 (prognostic effect). Patients treated within 12 h are more likely to profit from treatment. In multivariate analysis, there is no clear trend to benefit from LIF even in patients with young age, no CHD and early treatment. Based on this preliminary report on a rather small sample size, we do not recommend LIF in CRAO patients.

Cardiovascular Risk Factors in Central Retinal Artery Occlusion: Results of a Prospective and Standardized Medical Examination

PURPOSE

To analyze the underlying risk factors in patients with nonarteritic central retinal artery occlusion (CRAO) in a well-defined and homogenous group of patients enrolled in the European Assessment Group for Lysis in the Eye (EAGLE) study.

DESIGN

Analysis of the cardiovascular risk factors in a prospective, randomized clinical trial.

PARTICIPANTS

Seventy-seven EAGLE patients with nonarteritic CRAO.

METHODS

Analysis of vascular risk factors and underlying diseases detected by questionnaire and standardized physical examination within 1 month after occlusion.

MAIN OUTCOME MEASURES

The standardized physical examination included carotid Doppler ultrasonography, echocardiography, electrocardiography, blood pressure monitoring, pulse rate, urine analysis, body mass index analysis, and laboratory tests.

RESULTS

Seventy-seven of 84 patients had complete datasets for analysis. Fifty-two (67%) patients had cardiovascular risk factors in their medical history, and comprehensive phenotyping identified at least 1 new risk factor in 60 patients (78%; 95% confidence interval, 67%-87%). Thirty-one (40%) had carotid artery stenosis of at least 70%. Eleven patients experienced a stroke, 5 of those within 4 weeks after the CRAO occurred. Arterial hypertension was found in 56 (73%) patients and was newly diagnosed in 12 (16%) study participants. Cardiac diseases were also highly prevalent (22% coronary artery disease, 20% atrial fibrillation, and 17% valvular heart disease).

CONCLUSIONS

Previously undiagnosed vascular risk factors were found in 78% of all CRAO patients. The most meaningful risk factor was ipsilateral carotid artery stenosis. A comprehensive and prompt diagnostic work-up is mandatory for all CRAO patients.

Current endovascular treatment options for central retinal arterial occlusion: a review

Central retinal artery occlusion, although relatively rare, is an ophthalmological emergency. If left untreated, complete blindness will ensue. Conventional therapies have not significantly improved outcomes compared with the natural history of the disease. Several case series of more recent endovascular approaches, such as intraarterial fibrinolysis, report successful outcomes. Still other studies regarding intraarterial fibrinolysis do not demonstrate any significantly better outcomes, with some even indicating increased complication rates. Therefore, the authors present a review of the current endovascular treatment options for central retinal artery occlusion.

A review of central retinal artery occlusion: clinical presentation and management

Central retinal artery occlusion (CRAO) is an ophthalmic emergency and the ocular analogue of cerebral stroke. Best evidence reflects that over three-quarters of patients suffer profound acute visual loss with a visual acuity of 20/400 or worse. This results in a reduced functional capacity and quality of life. There is also an increased risk of subsequent cerebral stroke and ischaemic heart disease. There are no current guideline-endorsed therapies, although the use of tissue plasminogen activator (tPA) has been investigated in two randomized controlled trials. This review will describe the pathophysiology, epidemiology, and clinical features of CRAO, and discuss current and future treatments, including the use of tPA in further clinical trials.

Intra-arterial delivery of cell therapies for stroke

Cell therapy is a novel investigational approach to enhance stroke recovery. Intra-arterial (IA) delivery has the potential advantage of selectively targeting cell therapies to the ischemic brain tissue. Over the past 10 years, IA cell delivery has been under investigation in patients with cardiac and peripheral vascular disease, and these studies have reported promising results. This article reviews the trial methodology and procedural details of these studies and discusses the rationale and challenges in designing IA cell therapy trials for ischemic stroke.

Study of the Efficacy of Intravenous Tissue Plasminogen Activator in Central Retinal Artery Occlusion

Rationale

Central retinal artery occlusion is a stroke of the eye caused by a blockage of its main blood supply by platelet-fibrin clot. Systemic thrombolysis has been successful in restoring perfusion to ischaemic tissue by fibrin-platelet clot lysis in ischaemic stroke and myocardial infarction. Several open-label studies have demonstrated efficacy of thrombolysis in the treatment of central retinal artery occlusion, with up to 60–70% of treated subjects experiencing an improvement in visual acuity. Most of these are given intraarterially, which is an invasive procedure and not widely applicable to all treatment centres. An alternative is the intravenous infusion of tissue plasminogen activator using existing stroke thrombolysis protocols. A systematic review of all observational studies of intravenous tissue plasminogen activator in acute central retinal artery occlusion showed that 48·5% of subjects had a four line or more visual acuity improvement with an acceptable rate of haemorrhagic complications, creating the equipoise necessary to conduct a randomised controlled trial.

Aim

To determine the efficacy of intravenous thrombolysis in acute treatment of central retinal artery occlusion.

Design

A phase II, placebo-controlled, double-blind, randomised controlled trial comparing intravenous tissue plasminogen activator at 0·9 mg/kg to placebo (normal saline) 100 ml in a 1 : 1 block randomisation.

Study outcome

The primary outcome measure is an improvement of three lines or more on the Snellen visual acuity chart, which signifies a doubling of the visual angle.

Intra-arterial thrombolysis for central retinal artery occlusion: two cases report

Central retinal artery occlusion (CRAO) causes severe visual loss in affected eye and vision does not recover in more than 90% of the patients. It is believed that it occurs by occlusion of the central retinal artery with small emboli from atherosclerotic plaque of internal cerebral artery. Retina is a part of the brain, thus basically CRAO is corresponding to acute occlusion of intracerebral artery and retinal ischemia is to cerebral stroke. Therefore, intra-arterial thrombolysis (IAT) has been considered as a treatment method in CRAO. Recently, we treated 2 patients diagnosed as CRAO and could achieve complete recanalization on fundus fluorescein angiogram with IAT. Of them, one recovered visual acuity to 20/25. We report our 2 CRAO cases treated with IAT and discuss technical aspects for IAT and management of patient. To the best of our knowledge, this is the first Korean report of IAT for CRAO.

Intra-arterial thrombolysis for acute central retinal artery occlusion

OBJECTIVE

In this study, we aimed at exploring the effect and safety of local intra-arterial thrombolysis on acute central retinal artery occlusion.

METHODS

Retrospective data analysis of 49 consecutive acute central retinal occlusion patients was performed. All the patients were treated with urokinase perfusion through the ophthalmology artery within the first 6 hours after central retinal artery occlusion attack. Conventional treatments including intra-ocular pressure decreasing, microcirculation improvement, neuroprotection and antiplatelet aggregation were conducted. The visual acuity (with International Snellen Chart) and field of vision were detected after thrombolysis. The complications and adverse events were observed.

RESULTS

Recanalization was found in 71% of patients. The visual acuity improvement was greater in the recanalization group (n=35) than in the non-recanalization group (n=14). The averaged visual acuity was 0.15+/-0.02, 0.25+/-0.03 and 0.4+/-0.05 after 2, 28 days and 6 months, respectively. Of the patients, 24.5% regained >0.6 of visual acuity, and the visual field deficit was less than 30% in 34.7% of patients after 28 days. Six months later, 36.7% patients regained visual acuity of >0.6, and the field deficit was less than 30% in 44.9% of patients. The difference between visual acuity in recanalization (0.6+/-0.04) and non-recanalization (0.002+/-0.0012) patients after 6 months after thrombolysis was significant (p>0.05).

CONCLUSIONS

Intra-arterial thrombolysis could obviously improve the short- and long-term visual function for patients with acute central retinal artery occlusion within 6 hours of symptom onset.

Thrombolytic therapy in central retinal artery occlusion: cutting edge therapy, standard of care therapy, or impractical therapy?

PURPOSE OF REVIEW

Numerous therapeutic options have been suggested for the treatment of central retinal artery occlusion (CRAO) such as ocular massage, anterior chamber paracentesis, physical exercise, and medication-induced reduction of intraocular pressure. Because of the lack of a proven effective treatment for CRAO, there has been a strong effort to develop alternative therapies. Recently, thrombolytic therapy has been suggested as a viable therapy for CRAO. The aim of this review is to provide an update on the progress of thrombolytic therapy for CRAO.

RECENT FINDINGS

Although there is no consensus on a standardized treatment regimen for CRAO, emerging evidence suggests that thrombolytic therapy may be effective if administered promptly. Despite the benefit of thrombolytic therapy, on the basis of the results of case reports and case series, randomized controlled studies are necessary to ultimately prove the effectiveness of the treatment.

SUMMARY

Thrombolytic therapy has yet to be validated as an effective treatment of CRAO. The execution of randomized, controlled trials is greatly needed to establish whether thrombolytic therapy can be considered standard of care therapy for CRAO.

Interventions for acute non-arteritic central retinal artery occlusion

BACKGROUND

Acute central retinal artery occlusion (CRAO) occurs as a sudden interruption of the blood supply to the retina and results in an almost complete loss of vision in the affected eye. There is no generally agreed treatment regimen although a number of therapeutic interventions have been proposed.

OBJECTIVES

The objective of this review was to examine the effects of treatments used for acute non-arteritic CRAO.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (which contains the Cochrane Eyes and Vision Group Trials Register) (The Cochrane Library, Issue 3, 2008), MEDLINE (January 1966 to September 2008), EMBASE (January 1980 to September 2008) and the reference lists of relevant papers.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) only in which one treatment aimed to re-establish blood supply to the retina in people with acute CRAO was compared to another treatment.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed the search results for relevant trials. Discrepancies were resolved by discussion.

MAIN RESULTS

We found two RCTs that met our inclusion criteria.

AUTHORS' CONCLUSIONS

The included studies in this review were small and from single centres. Neither study was completely clear about it's method of treatment allocation. One study described the use of pentoxifylline tablets (three 600 mg tablets daily) and the other the use of enhanced external counterpulsation (EECP) combined with haemodilution. Both studies indicated improved retinal perfusion in the non-control group but neither showed an improvement in vision. Large, well-designed RCTs are still required to establish the most effective treatment for acute CRAO. These studies should be looking at factors important to the patient i.e. improved vision with acceptable risk/side-effects.

Intravenous thrombolysis with low-dose recombinant tissue plasminogen activator in central retinal artery occlusion

PURPOSE

To evaluate the beneficial effect of intravenous thrombolysis aiming at rapid restoration of blood flow during the early hours of a central retinal artery occlusion (CRAO).

DESIGN

Interventional case series.

METHODS

In the present study, we prospectively evaluated the visual outcome after thrombolytic treatment with low-dose (50 mg) rt-PA (recombinant tissue plasminogen activator) and concomitant intravenous heparinization in patients with acute CRAO, best-corrected visual acuity (BCVA) < or = 20/100, and onset of symptoms within 12 hours prior to treatment.

RESULTS

Twenty-eight patients (28 eyes) were included in this study. Final visual acuity was improved three or more lines in nine eyes (32%), stable in 18 (64%), and worse in one eye. Time to treatment < or = 6.5 hours was associated with a better gain of lines of vision (P = .004). Seven of 17 eyes (41%) that received thrombolytic treatment within the first 6.5 hours achieved a final BCVA > or = 20/50, compared to none in the subgroup of patients with onset to treatment >6.5 hours (P = .023). We observed no serious adverse events.

CONCLUSIONS

Our findings indicate that thrombolytic treatment with intravenous low-dose rt-PA is of value for an improved visual recovery in patients with acute CRAO, if administered within the first 6.5 hours after the onset of symptoms.

Management of acute central retinal artery occlusion

Central retinal artery occlusion (CRAO) is considered to be an acute stroke of the eye that results in profound visual loss. Spontaneous recovery rates are poor. Most CRAOs are caused by thromboembolism in the central retinal artery. Current standard therapies for CRAO that aim to restore perfusion to the retina and optic nerve head have not been shown to alter the natural course of the disease. Thrombolytic therapy for acute management of CRAO has shown promise in nonrandomized studies with regard to improving visual outcomes. A randomized controlled trial will be required to confirm the efficacy of thrombolytic therapy before it can be recommended for use in CRAO in daily clinical practice.

Local intraarterial fibrinolysis administered in aliquots for the treatment of central retinal artery occlusion: the Johns Hopkins Hospital experience

BACKGROUND AND PURPOSE

Central retinal artery occlusion results in acute visual loss with poor spontaneous recovery. Current standard therapies do not alter the natural history of disease. Several open-label clinical studies using continuous infusion of thrombolytic agents have suggested that local intraarterial fibrinolysis (LIF) is efficacious in the treatment of central retinal artery occlusion. The aim is to compare the visual outcome in patients with acute central retinal artery occlusion of presumed thromboembolic etiology treated with LIF administered in aliquots with that of patients treated with standard therapy.

METHODS

We conducted a single-center, nonrandomized interventional study of consecutive patients with acute central retinal artery occlusion from July 1999 to July 2006.

RESULTS

Twenty-one patients received LIF and 21 received standard therapy. Seventy-six percent of subjects in the LIF group had a visual acuity improvement of one line or more compared with 33% in the standard therapy group (P=0.012, Fisher exact). Multivariate logistic regression controlling for gender, history of prior stroke/transient ischemic attack, and history of hypercholesterolemia showed that patients who received tissue plasminogen activator were 36 times more likely to have improvement in visual acuity (P=0.0001) after adjusting for these covariates. Post hoc analysis showed that patients who received tissue plasminogen activator were 13 times more likely to have improvement in visual acuity of 3 lines or more (P=0.03) and 4.9 times more likely to have a final visual acuity of 20/200 or better (P=0.04). Two groin hematomas were documented in the LIF group. No ischemic strokes, retinal or intracerebral hemorrhages were documented.

CONCLUSIONS

LIF administered in aliquots is associated with an improvement in visual acuity compared with standard therapy and has few side effects.

Stroke and visual rehabilitation

Many patients will experience some type of visual dysfunction following a stroke. The visual changes associated with stroke can be categorized as sensory (visual acuity and visual field), motor (extraocular muscle motility), and perceptual. These disturbances affect the patient's quality of life and can impede overall rehabilitation. Many of these impairments can be addressed by simple yet effective techniques. As a result, vision rehabilitation specialists are becoming an important part of the multidisciplinary stroke rehabilitation team.

Interventional neuroradiology for the ophthalmologist

The past two decades have witnessed major advances in diagnosing vascular conditions that affect blood supply and hemorrhagic risk to the brain and the eye. Technological improvements have resulted in the ability to better radiologically image the cerebrovascular system and to deliver pharmacological and embolic agents that have high specificity. Neuroradiological interventional therapy has become the preferred option in managing many conditions that were previously treated by standard neurosurgical procedures. Some of these conditions were considered either inoperable or treatable only with unacceptable neurosurgical risks. This article reviews the current state of the neuroradiological interventional management in conditions that may be encountered in ophthalmological practice.

Thrombolysis for Central Retinal Artery Occlusion

Central retinal artery occlusion (CRAO) frequently causes severe and irreversible visual loss. For many years, various conservative treatments have been proposed for acute CRAO, but their efficacy remains unproven. Over the past 20 years, CRAO has also been treated with thrombolytic agents administered intravenously or intra-arterially. However, all thrombolytic studies are retrospective and uncontrolled, so that the benefit of this treatment remains uncertain. A prospective controlled clinical trial is ongoing in Europe and should provide more reliable information. Even if this trial demonstrates a benefit, thrombolytic treatment is unlikely to become widespread in the management of CRAO unless it can be deployed quickly after the event.

Lysetherapie vs. konservative Therapie

In the prospective, randomised and multicenter EAGLE study, the therapeutic efficiency of local intra-arterial fibrinolysis (LIF) versus conservative treatment is being tested in patients with an acute central retinal artery occlusion (CRAO). The most important inclusion criteria are: (1) age between 18-75 years, (2) CRAO not older than 20 h, and (3) visual acuity <0.32. The primary study endpoint is the visual acuity before and 1 month after therapy. The study was started in 2002. To August 2006, 63 of the 200 required patients have been included in the study at 17 medical centers in Germany, Switzerland and Austria.

Multicenter study of the European Assessment Group for Lysis in the Eye (EAGLE) for the treatment of central retinal artery occlusion: design issues and implications. EAGLE Study report no. 1 : EAGLE Study report no. 1

BACKGROUND

The natural course of central retinal artery occlusion (CRAO) often leads to legal blindness in the affected eye. To date, none of the conservative therapies had proven effective in retrospective studies. In 1991, a new minimally invasive therapy was started in patients with an acute CRAO. This therapy, namely, local intra-arterial fibrinolysis, is comparable to the minimally invasive therapy in patients with an acute ischemic stroke. In pilot studies, it showed promising results in comparison with conservative treatments. The efficacy of this method is now being investigated in a randomized multicenter study.

METHODS

The European Assessment Group for Lysis in the Eye (EAGLE) started a prospective and randomized multicenter study in 2002 to evaluate therapeutic efficacy. Inclusion criteria are age between 18 and 75 years and a CRAO not older than 20 h with a visual acuity less than 0.32. The most important exclusion criteria are branch retinal artery occlusion (BRAO), cilioretinal arteries supplying the macula, and serious general disease. After randomization the patient is treated by conservative or local intra-arterial lysis therapy. The conservative regime included bulbus massage, lowering intraocular pressure with topical beta-blocker and acetazolamide, acetylsalicylic acid, heparin, and-depending on the hematocrit-isovolemic hemodilution. In case of local intra-arterial fibrinolysis, a maximum of 50 mg rtPA is injected into the ophthalmic artery by the neuroradiologist. During the following 5 days, all patients are treated with heparin. Primary study end point is visual acuity 1 month after therapy in comparison with visual acuity before therapy. The calculated sample size is 100 patients per subtrial (a total of 200 patients). The study was started in June 2002. To April 2005, 47 patients were included.

CONCLUSIONS

The EAGLE Study is the first randomized prospective clinical trial to compare conservative medical treatment and local intra-arterial fibrinolysis in patients with CRAO. The results of this study should enable ophthalmologists and neuroradiologists to improve the therapy of patients with acute CRAO. To April 2005, treatment is only justified in randomized multicenter studies because of the limited therapeutical visual outcome. We welcome new study centers to join.

Selective intraarterial fibrinolysis of acute central retinal artery occlusion

PURPOSE

To evaluate the outcome of our patients with central retinal artery occlusion after local fibrinolysis and to compare these data with results reported in the literature.

MATERIAL AND METHODS

Over a period of 7 years, 22 patients (11 male, 11 female, mean age 64.6 +/- 12.1 years) were treated with super-selective local fibrinolysis. In 1 case, treatment was carried out via the maxillary-ophthalmic anastomoses due to preexisting occlusion of the ipsilateral internal carotid artery. The latency period from the onset of symptoms to the beginning of therapy was 7.6 +/- 1.8 h. Urokinase was used in 7 cases (300,000-1.1 million units) and recombinant tissue plasminogen activator (20-40 mg) was applied in 15 patients. Visual acuity and fundus were examined before and after treatment.

RESULTS

One patient (1/22 = 4.6%) recovered completely and regained a visual acuity of 20/20. Six patients (6/22 = 27.3%) showed a marked improvement with a range of visual outcome from 20/800 to 20/320. In 2 cases (2/22 = 9.1%) only a slight improvement was observed, with a visual outcome allowing detection of hand movements. In 13 cases (13/22 = 59.1%) no change in visual acuity as a result of treatment was observed. In 2/22 cases (9.2%) reversible neurological side-effects occurred, in 1 case suffered a stroke, and in another case intracerebral bleeding was observed.

CONCLUSION

In our study, the recovery of visual acuity and the complication rate were not as positive as reported in the literature.

Massive spontaneous choroidal hemorrhage

PURPOSE

To describe the course, management, and prognosis of massive spontaneous choroidal hemorrhage.

METHODS

The presenting visual acuity, ocular findings, duration to surgical intervention, and outcomes of five patients were retrospectively reviewed.

RESULTS

Five eyes from four patients (median age, 80 years; range, 66-85 years) were studied. The patients were observed from 4 to 72 months (median, 33 months). Three patients were on anticoagulation therapy with warfarin; one patient had bilateral involvement with no history of anticoagulation therapy. Three patients were hypertensive, and three of the four had been diagnosed with age-related macular degeneration. Four eyes underwent choroidal drainage procedures, and one was observed. In all patients whose choroids were drained, the final vision was no light perception.

CONCLUSIONS

Massive spontaneous choroidal hemorrhage may be associated with hypertension, systemic anticoagulation, advanced age, and age-related macular degeneration. Final visual acuities are generally poor.

Interventions for acute non-arteritic central retinal artery occlusion

BACKGROUND

Acute central retinal artery occlusion occurs as a sudden interruption of the blood supply to the retina and results in an almost complete loss of vision in the affected eye. There is no generally agreed treatment regimen although a number of therapeutic interventions have been proposed.

OBJECTIVES

The objective of this review is to examine the effects of treatments used for acute non-arteritic central retinal artery occlusion.

SEARCH STRATEGY

We searched the Cochrane Controlled Trials Register - CENTRAL/CCTR, which contains the Cochrane Eyes and Vision Group specialised register (Cochrane Library Issue 4, 2001), MEDLINE (1966 to August 2001) and EMBASE (1980 to September 2001). We searched the reference lists of relevant papers for trials.

SELECTION CRITERIA

We included only randomised controlled trials in which one treatment aimed to re-establish blood supply to the retina in people with acute central retinal artery occlusion was compared to another treatment.

DATA COLLECTION AND ANALYSIS

Two reviewers independently assessed the search results for trials to be included in the review. Discrepancies were resolved by discussion.

MAIN RESULTS

We found no randomised controlled trials that met our inclusion criteria.

REVIEWER'S CONCLUSIONS

There is currently not enough evidence to decide which, if any, interventions for acute non-arteritic central retinal artery occlusion would result in any beneficial or harmful effect. Well-designed randomised controlled trials are needed to establish the most effective treatment.

Local intra-arterial fibrinolysis for acute occlusion of the central retinal artery: a meta-analysis of the published data

BACKGROUND/AIM

Central retinal artery occlusion (CRAO) is typically associated with a poor visual outcome. Several favourable reports of local intra-arterial fibrinolysis (LIF), which involves the superselective administration of a thrombolytic agent directly into the ophthalmic artery, have appeared in the recent literature. The aim of this study was to critically appraise these studies in a collective fashion.

METHODS

A meta-analysis was performed of all the published literature germane to LIF in cases of CRAO.

RESULTS

Of the 16 studies identified, all were retrospective and non-randomised. After correction for data duplication, the results of LIF in 100 patients can be reported. A final acuity of 6/6 or better was seen in 14% of patients following LIF, and a visual result of 6/12 or better was seen in 27% of subjects. A poor final acuity of 3/60 or worse was seen in 60.6% of eyes treated with local intra-arterial fibrinolysis. These results compare favourably with conventional forms of therapy. Potentially serious complications were seen in four patients, but no patient suffered a permanent neurological deficit.

CONCLUSION

The results of this study suggest that there may be a marginal visual benefit associated with LIF compared with conventional management of CRAO. However, the methodology of the cited studies was often unsatisfactory, and a randomised controlled trial of LIF in cases of CRAO is justified. Outside of a randomised clinical trial, the use of superselective fibrinolytic therapy for CRAO cannot be recommended on the basis of current evidence.

Selective thrombolysis of central retinal artery occlusion without long-term systemic heparinization

BACKGROUND

A central retinal artery occlusion is a potentially blinding retinal vascular event with no effective treatment regimen available. Recently, a few reports have described improved vision in eyes with central retinal artery occlusions after selective fibrinolytic therapy followed by long-term systemic anticoagulation. Acceptance of this treatment, however, has been hampered by a paucity of confirmatory reports and its potential for producing serious hemorrhagic complications. Our report independently confirms the beneficial effects of selective thrombolysis, even with the use of only short-term, post-procedure systemic heparinization.

METHODS

A case report of selective fibrinolysis of an occluded central retinal artery using urokinase infusion into the ophthalmic artery followed with only 12 h of systemic heparinization is described.

RESULTS

A 65-year-old man presenting with a central retinal artery occlusion of less than 4-h duration enjoyed an improvement of vision from counting-fingers acuity to 20/20 after selective fibrinolysis with urokinase and only 12 h of systemic heparinization. No hemorrhagic or thrombotic complications occurred.

CONCLUSIONS

Selective thrombolysis with urokinase followed by short-term systemic heparinization can effectively treat a central retinal artery occlusion. Whereas the authors acknowledge that a single case does not prove that short-term heparinization is better than long-term heparinization, it does show that the latter is not always required.

Selective intra-arterial fibrinolysis of acute central retinal artery occlusion

BACKGROUND AND PURPOSE

Occlusion of the central retinal artery (CRAO) causes a sudden decrease of monocular vision. Because early restoration of blood flow may improve outcome, we attempted to treat CRAO with selective intra-arterial fibrinolysis.

METHODS

Intra-arterial fibrinolysis was performed within 6 hours after symptom onset in 17 patients with thromboembolic CRAO. Symptoms were painless, acute and severe decrease of vision. Urokinase (100 000 to 900 000 IU) was given through a microcatheter into the ophthalmic artery over 10 to 90 minutes. For comparison, the history and visual outcome of 15 control patients who did not receive fibrinolytics were evaluated. In both groups some of the patients underwent paracentesis and/or received carboanhydrase inhibitors.

RESULTS

Patients who underwent fibrinolysis fared better than control patients (P=0.01). Three patients (17.6%) recovered completely after fibrinolysis and regained visual acuity of 20/20 (n=2) to 25/20 (n=1). Two additional patients (11.8%) showed a marked improvement to a visual acuity of 20/30. In 6 patients (35. 3%) vision improved slightly. They were able to count fingers, detect hand movements, or perceive light. In 6 patients (35.3%), fibrinolytic treatment was without effect. Among control patients, 1 patient (6.7%) showed partial, 4 patients (26.7%) minimal, and 10 (66.7%) no improvement of vision.

CONCLUSIONS

A complete or marked improvement of visual acuity was achieved in one third of intra-arterial fibrinolysis patients but in none of the control patients. Intra-arterial fibrinolysis seems to have the potential to "lighten" the spontaneously poor outcome of CRAO.

Acute visual loss and other disorders of the eyes

This article outlines neuro-ophthalmic findings and diseases which may present in an emergency setting. The abnormal optic disc, visual loss, double-vision and disorders of gaze, skew deviation, and the neuro-ophthalmology of vascular lesions, intracerebral hemorrhage, increased intracranial pressure, neuromuscular emergencies, metabolic disturbances, and trauma are all reviewed.

Hemorrhagic ocular complications associated with the use of systemic thrombolytic agents

OBJECTIVE

This study aimed to report three patients with hemorrhagic ocular and orbital complications associated with the use of systemic thrombolytic agents.

DESIGN

The study design was a retrospective small case series.

PARTICIPANTS

Three eyes of three patients were studied.

INTERVENTION

Surgical procedures to reduce intraocular pressure or relieve optic nerve compression were performed.

MAIN OUTCOME MEASURES

Visual acuity and intraocular pressure were measured.

RESULTS

Three patients received an intravenous thrombolytic agent on diagnosis of an acute myocardial infarction. One patient had a spontaneous suprachoroidal hemorrhage develop with secondary acute angle closure glaucoma shortly after receiving tissue plasminogen activator. Another patient had an orbital hemorrhage develop on receiving tissue plasminogen activator 4 days after an uncomplicated cataract extraction. The third patient experienced an orbital hemorrhage while receiving streptokinase 1 day after undergoing an external levator resection. Two patients suffered significant visual loss due to glaucoma or compressive optic neuropathy.

CONCLUSIONS

The onset of eye pain or visual loss after the administration of a systemic thrombolytic agent should alert the physician to the possibility of an ocular or adnexal hemorrhage. Prompt diagnosis and treatment can improve the likelihood of a favorable visual outcome.