Thrombolysis for 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.

Retinal Artery Occlusion: A Review of Current Management Practices

Retinal artery occlusion (RAO) is a well-characterized ischemic ophthalmic event that may result in sudden and devastating vision loss. The etiology of RAO may vary including both arteritic and non-arteritic causes and the location of the lesion can extend from the ophthalmic artery to the branches of the central retinal artery. Given this variable causes of RAO, the clinical presentation and extent of vision loss may also differ from case to case, necessitating a prompt and thorough evaluation, including a full stroke work up. While there is currently no widely accepted standard for the treatment of RAO, there are several proposed methods that have been or are currently being investigated through retrospective studies and prospective trials. The current article aims to provide a review of the pathophysiology, clinical presentation, and management of RAO in addition to presenting a systematic review of recently published studies on treatment options for RAO.

Early REperfusion therapy with intravenous alteplase for recovery of VISION in acute central retinal artery occlusion (REVISION): Study protocol of a phase III trial

RATIONALE

Meta-analyses of case series of non-arteritic central retinal artery occlusion (CRAO) indicate beneficial effects of intravenous thrombolysis when initiated early after symptom onset. Randomized data are lacking to address this question.

AIMS

The REperfusion therapy with intravenous alteplase for recovery of VISION in acute central retinal artery occlusion (REVISION) investigates intravenous alteplase within 4.5 h of monocular vision loss due to acute CRAO.

METHODS

This study is the randomized (1:1), double-blind, placebo-controlled, multicenter adaptive phase III trial.

STUDY OUTCOMES

Primary outcome is functional recovery to normal or mildly impaired vision in the affected eye defined as best-corrected visual acuity of the Logarithm of the Minimum Angle of Resolution of 0.5 or less at 30 days (intention-to-treat analysis). Secondary efficacy outcomes include modified Rankin Score at 90 days and quality of life. Safety outcomes include symptomatic intracranial hemorrhage, major bleeding (International Society on Thrombosis and Haemostasis definition) and mortality. Exploratory analyses of optical coherence tomography/angiography, ultrasound and magnetic resonance imaging (MRI) biomarkers will be conducted.

SAMPLE SIZE

Using an adaptive design with interim analysis at 120 patients, up to 422 participants (211 per arm) would be needed for 80% power (one-sided alpha = 0.025) to detect a difference of 15%, assuming functional recovery rates of 10% in the placebo arm and 25% in the alteplase arm.

DISCUSSION

By enrolling patients within 4.5 h of CRAO onset, REVISION uses insights from meta-analyses of CRAO case series and randomized thrombolysis trials in acute ischemic stroke. Increased rates of early reperfusion and good neurological outcomes in stroke may translate to CRAO with its similar pathophysiology.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT04965038; EU Trial Number: 2023-507388-21-00.

Update on central retinal artery occlusion

The medical condition referred to as "central retinal artery occlusion" (CRAO) was first documented by Albrecht von Graefe in 1859. Subsequently, CRAO has consistently been identified as a serious medical condition that leads to substantial visual impairment. Furthermore, it is correlated with vascular complications that have the potential to affect crucial organs such as the brain and heart. A considerable amount of research has been extensively published on the various aspects of this topic, which is marked by notable debates and misconceptions, especially regarding its management and outcomes. The primary aim of this review article is to analyze the latest developments in the understanding of CRAO, which includes its causes, techniques for retinal imaging, systemic evaluation, and therapeutic strategies, such as vitrectomy. This review article offers readers a comprehensive learning experience to gain knowledge on the fundamental principles and recent advancements in CRAO.

Unusual case of retinal arterial branch occlusion: possible variant of Sneddon syndrome

Sneddon's syndrome (SS) manifests through multiple strokes and livedo reticularis. Livedoid vasculopathy (VL) is characterized by a long history of foot and leg ulceration and histopathology indicating a thrombotic process. Arterial retinal branch occlusion is described in a 52-year-old male with VL. He did not present noticeable laboratory abnormalities, such as antiphospholipid antibodies, or a history of strokes. Retinal artery occlusion accompanied by VL could be a variant of Sneddon's syndrome. Optical coherence tomography angiography revealed a reduction in the macula's vascular layers in the asymptomatic eye, indicating localized microvascular changes as an evolving marker in the pathogenesis of SS.

Branch retinal artery occlusion with congenital common carotid artery and internal carotid artery occlusion: A case report

PURPOSE

To report a case of branch retinal artery occlusion (BRAO) of the left eye combined with left congenital common carotid artery occlusion (CCAO) and internal carotid artery occlusion (ICAO).

METHODS

Case report.

RESULTS

A 36-year-old man presented with sudden vision loss of only the left eye without any signs or symptoms of brain diseases. Fluorescein fundus angiography (FFA) showed left BRAO, and computed tomography angiography (CTA) of the head and neck showed entire left CCAO and ICAO. The patient's left vertebral artery was anastomosed with the left occipital artery via the muscular branch, supplying blood retrogradely to the left external carotid artery. The right internal carotid artery compensated for blood supply to the left anterior cerebral artery and middle cerebral artery via anterior communication, and the left posterior communication artery compensated for blood supply to the left middle cerebral artery.

CONCLUSIONS

To our knowledge, this study was the first to report a case of BRAO combined with congenital CCAO and ICAO with vision loss as the first symptom and proposed the importance of head and neck examination in retinal artery occlusion at the first visit to a doctor.

Progress in central retinal artery occlusion: a narrative review

Central retinal artery occlusion (CRAO) is a catastrophic ophthalmic emergency that severely impairs a patient's visual function, often reducing visual acuity to counting fingers or worse. Progress in CRAO research has provided new information regarding its epidemiological characteristics and led to useful assessments through various ophthalmic examinations. Additional insights about CRAO have been gained through studies of its pathophysiological mechanisms, improving intervention timing and enhancing patient prognosis. Treatment for CRAO has evolved, particularly with assistance from surgical instruments and surgical robots. Although surgical treatment is now possible, this option is not widely recognized by ophthalmologists. Conservative therapies have limited benefits compared with the natural course of disease. Recently, pars plana vitrectomy plus endovascular surgery has received considerable interest among ophthalmologists because of its potential efficacy in the treatment of CRAO. Considering the inconsistencies in rationale and efficacy of CRAO treatment modalities, it is important to distinguish between treatment effects and the natural courses of various CRAO subclasses. This narrative review explores progress in CRAO epidemiology, pathophysiology, ophthalmic examination, and treatment.

Central retinal artery occlusion - detection score

Purpose

To investigate the sensitivity and specificity of central retinal artery occlusion (CRAO)-Detection Score in diagnosing CRAO via questionnaire and without fundoscopy.

Methods

This prospective study enrolled 176 emergency patients suffering from acute visual loss, of whom 38 were suffering from CRAO. Before conducting any examination, we administered our questionnaire containing six questions, followed by a thorough ophthalmologic examination to make the diagnosis. Statistical analysis involved a LASSO penalised multivariate logistic regression model.

Results

Our receiver operating characteristic (ROC) analysis based on a LASSO penalised multivariate logistic regression model showed an area under the curve (AUC) of 0.9 - three out of six questions were selected by LASSO. Interestingly, the unweighted ROC analysis of only two questions (Short CRAO-Detection Score) yielded similar results with an AUC of 0.88. The short CRAO-Detection Score of 2 yielded 14% (4/28) false positive patients.

Conclusion

This prospective study demonstrates that a high percentage of CRAO patients are detectable with a questionnaire. The CRAO-Detection Score might be used to triage patients suffering acute visual loss, which is important as intravenous fibrinolysis seem to be time-dependent to be effective.

Central retinal artery occlusion in a patient with sickle cell disease treated with recombinant tissue plasminogen activator

Central retinal artery occlusion is a rare ophthalmological complication of sickle cell disease, usually provoked by additional contributing risk factors and its treatment remains controversial. We describe a patient with sickle cell disease and a spontaneous central retinal artery occlusion of his left eye that probably has good result from intravenous thrombolysis. We want to add sickle cell disease as rare etiological cause of central retinal artery occlusion and perpetuate evidence of intravenous recombinant tissue plasminogen activator administration in this condition.

Central retinal artery occlusion: a retrospective study of disease presentation, treatment, and outcomes

OBJECTIVE

A central retinal artery occlusion (CRAO) represents a form of ocular stroke with poor visual prognosis. CRAO shares a common pathophysiology with cerebral ischemic stroke but presents unique diagnostic and management challenges leading to variability in clinical practice. This study aims to assess the presentation, treatment, and outcomes of CRAO at a tertiary care centre in Canada over 2 years and elucidate potential areas for improvement in the care of these patients.

METHODS

Single-institution retrospective review including 27 patients diagnosed with CRAO from March 2018 to March 2020 in Edmonton, Alberta.

RESULTS

Most patients with CRAO presented to eye care providers (14 of 27); others presented to the emergency department (10 of 27) or family physicians (2 of 27). Three patients (11.1%) presented within 4.5 hours of symptom onset. At presentation, 81% of patients had visual acuity of 20/400 or worse in the affected eye. No patients received thrombolysis. The majority of CRAO cases had a nonarteritic etiology (92.6%). All patients had at least one pre-existing vascular risk factor. Forty-eight percent of patients received escalated medical therapy. Ipsilateral carotid stenosis was identified in 5 patients (18.5%); 3 patients required carotid endarterectomy. Two patients were diagnosed with atrial fibrillation. Two patients experienced symptomatic cerebral ischemia within 6 weeks of CRAO.

CONCLUSIONS

The majority of patients with CRAO presented to eye care providers, and few present within the potential window for thrombolysis of 4.5 hours, highlighting the need for public awareness strategies. Our cohort highlights the significant rate of systemic comorbidity that exists in these patients.

INTRAVENOUS THROMBOLYTIC THERAPY FOR ACUTE NONARTERITIC CENTRAL RETINAL ARTERY OCCLUSION. A REVIEW

Central retinal artery occlusion (CRAO) is a form of acute ischemic stroke. It is a critical condition that often leads to severe visual loss or blindness and can be a harbinger of further cerebrovascular events. Due to the lack of scientific data, there are no effective evidence-based forms of therapy for this condition. None of the conservative therapies have proven effective. The results of some previously published studies suggest a benefit of intravenous thrombolytic therapy in the same regimen as in the treatment of ischemic stroke. This work aims to present an overview of published clinical studies focused on the use of intravenous thrombolysis for CRAO, evaluate its efficacy and safety, and propose an optimal diagnostic and therapeutic algorithm for acute management of CRAO. Summary statistics of patient data from relevant studies indicate that a significant visual acuity improvement was achieved by a total of 45 % of patients receiving alteplase within 4.5 hours of symptoms onset. The occurrence of adverse events in this time window was not significant. Intravenous thrombolytic therapy in CRAO thus appears to be effective and safe. However, we still lack data from adequate prospective randomized controlled trials to confirm this conclusion. To date, two randomized trials are being conducted. The intravenous thrombolysis administration, patient monitoring, etiologic workup, and setting of effective secondary prevention should be ensured at the centre of highly specialized cerebrovascular care. Urgent transport of the CRAO patient to the nearest centre is essential.

[Update on intravenous lysis treatment : The REVISION trial]

BACKGROUND

To date, no evidence-based treatment for acute non-arteritic central retinal artery occlusion (CRAO) exists. Considering the limited ischemia tolerance of the retina and the results of multiple case series, increasing expectations are directed towards an early intravenous thrombolysis within 4.5 h after CRAO onset.

OBJECTIVE

The current literature regards timely retinal reperfusion as the only potentially beneficial therapeutic option to treat non-arteritic CRAO. Available data on the efficacy and safety of thrombolysis in CRAO are presented and discussed. On the basis of these data, the prospective, randomized, double-blind, placebo-controlled REVISION trial (early REperfusion therapy with intravenous alteplase for recovery of VISION in acute central retinal artery occlusion) will shortly be initiated in 25 centers across Germany in order to investigate early intravenous thrombolysis in acute CRAO. The main inclusion criteria of the REVISION trial are outlined, which may help ophthalmologists to identify study candidates and facilitate rapid referral to a study center.

CONCLUSION

The efficacy of intravenous thrombolysis in acute ischemic stroke is critically time dependent. This may also be assumed in acute CRAO; however, definite evidence still needs to be provided. Until then, the motto "time is retina" should be applied and intravenous thrombolysis should be offered to CRAO patients as part of randomized trials (such as REVISION). According to the current literature, other acute treatment approaches (such as paracentesis) are not indicated.

An Efficacy and Safety Study of Intra-arterial Recanalization of Occluded Ophthalmic Arteries in Patients with Monocular Blindness Caused by Injection of Hyaluronic Acid in Facial Tissues

PROPOSE

To evaluate the efficacy and safety of recanalizing hyaluronic acid-occluded retinal central artery by intra-arterially infusing hyaluronidase.

METHODS

Between December 2015 and December 2016, 30 patients with monocular blindness due to the injection of hyaluronic acid in facial tissue underwent ophthalmic artery recanalization. The outcome of the intra-arterial treatment was retrospectively reviewed. The fundus was examined 24 hours after the treatment to observe revisualization of the retinal arteries. The success rate of intra-arterial recanalization of the ophthalmic artery, procedure-related complications, visual acuity recovery, eyeball and eyelid movement restoration was followed up for up to 3 months.

RESULTS

The success rate of ophthalmic arterial catheterization was 100%. No interventional procedure-related adverse events were found. Twenty-six patients presented ptosis and 23 patients presented ocular motility disorders. The ptosis disappeared and 18 patients had normal eye movement after the intra-arterial therapy. Five of the 30 patients had visual improvement and four patients with complete vision loss gained some light perception. After the intra-arterial thrombolysis, digital subtraction angiographic imaging revealed enlarged and numerous branches of the ophthalmic artery and a clearer ring around the eye.

CONCLUSION

Intra-arterial infusion of hyaluronidase and mechanical recanalization is an effective and safe approach for recovering the visual acuity in the patients with monocular blindness caused by the migration of hyaluronic acid injected in the facial tissues.

LEVEL OF EVIDENCE IV

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Thrombolysis for Central Retinal Artery Occlusion in 2020: Time Is Vision!

BACKGROUND

Acute nonarteritic central retinal artery occlusion (CRAO) is an eye stroke with poor visual prognosis and no proven effective therapies. Given advances in acute stroke care, thrombolysis in CRAO merits critical re-examination. We review the evidence for intravenous (IV) and intra-arterial (IA) tissue plasminogen activator (tPA) in CRAO management.

EVIDENCE ACQUISITION

MEDLINE, Scopus, and Cochrane online databases were systematically searched from 1960 to present, for reports of acute IV or IA therapy with alteplase or tenecteplase in nonarteritic CRAO patients. English language case reports, case series, interventional studies, or randomized controlled trials were included. The study type, age and number of subjects, the regimen administered, the time since symptoms' onset, visual outcome, and safety reports were noted.

RESULTS

Use of IV thrombolysis with alteplase was reported in 7 articles encompassing 111 patients, with 54% of them receiving IV tPA within 4.5 hours of symptom onset, and none developing symptomatic intracranial or ocular hemorrhage. Six studies described IA alteplase administration, with only 18 of a total of 134 patients (13.4%) treated within the first 6 hours after visual loss. The reported adverse events were minimal. Visual outcomes post-IV and IA thrombolysis were heterogeneously reported; however, most studies demonstrated benefit of the respective reperfusion therapies when administered very early. We found no reports of tenecteplase administration in CRAO.

CONCLUSIONS

In 2020, nonarteritic CRAO patients should theoretically receive the same thrombolytic therapies, in the same time window, as patients with acute cerebral ischemia. Eye stroke and teleeye stroke code encounters must include an expert ophthalmologic evaluation to confirm the correct diagnosis and to evaluate for ocular signs that may help guide IV tPA administration or IA management. Future research should focus on developing feasible retinal penumbra imaging studies that, similar to cerebral tissue viability or perfusion imaging, can be incorporated into the thrombolysis decision-making algorithm.

Safety and Efficacy of Selective Intra-arterial Thrombolysis for Central Retinal Artery Occlusion

PURPOSE

The purpose of this study was to determine the efficacy and safety of selective intra-arterial thrombolysis in patients with central retinal artery occlusion (CRAO).

METHODS

Medical records for 44 eyes of 44 patients diagnosed with acute non-arteritic CRAO and thrombolysis between October 2010 and February 2019 were analyzed retrospectively. Based on visual acuity, fundoscopic findings, and fluorescein angiography, the patients were classified into three stages: incomplete, subtotal, and total. The perfusion state using the best-corrected visual acuity (BCVA), arm to retina time, and arteriovenous passage times, after 1 month, 6 months, and at the final visit after the procedure, were compared with baseline readings.

RESULTS

Improvement of visual acuity was confirmed in 31 out of 44 patients (70.45%). The mean BCVA of 44 patients changed from 1.65 ± 0.78 logarithmic minimum angle of resolution (logMAR) at the first visit to 1.18 ± 0.91 logMAR at the last visit (p = 0.114). The BCVA according to CRAO stage was 0.08 ± 0.11 logMAR for the incomplete stage at the first visit, 0.06 ± 0.05 logMAR (p = 0.933) 1 month after the procedure, and 0.05 ± 0.07 logMAR (p = 0.933) at the last visit. In the subtotal stage, the results were 1.81 ± 0.54 logMAR at the first visit, 1.63 ± 0.76 logMAR (p = 0.035) 1 month after the procedure, and 1.36 ± 0.85 logMAR (p = 0.014) at the last visit. For the total stage of BCVA, the result at the first visit was 2.36 ± 0.25 logMAR, and it was 2.30 ± 0.30 logMAR (p = 0.510) 1 month after the procedure, and 2.42 ± 0.30 logMAR (p = 0.642) at the last visit. Reperfusion was observed in 40 patients out of the 44 (90.91%).

CONCLUSIONS

Selective intra-arterial thrombolysis can be helpful in patients with subtotal CRAO in terms of visual improvement and retinal arterial reperfusion.

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.

Central retinal artery occlusion after catheter ablation of atrial fibrillation

Central retinal artery occlusion (CRAO) is a rare but severe and urgent complication of atrial fibrillation ablation. Awareness of this ophthalmologic complication and prompt treatment are needed because ischemic damage to the retina is irreversible from 4 hours after the onset of CRAO.

The Retrobulbar Spot Sign and Prominent Middle Limiting Membrane as Prognostic Markers in Non-Arteritic Retinal Artery Occlusion

Central retinal artery occlusion (CRAO) is characterized by the sudden, painless loss of vision. Typical sonographic and optic coherence tomography (OCT) findings are a retrobulbar spot sign and prominent middle limiting membrane (p-MLM) sign. It remains uncertain whether the retrobulbar spot sign alone or coinciding with the appearance of p-MLM sign is a prognostic marker for visual acuity and the development of secondary retinal ischemia after CRAO. In our prospective cohort study, we included patients with a non-arteritic central artery occlusion < 4 weeks. We examined the following parameters at prespecified time points: ultrasound examination of orbital cavity, Spectral Domain-OCT examination, visual acuity test, and fundoscopy and ultra-widefield angiography to diagnose retinal vascularization. The presence of p-MLM sign in SD-OCT after CRAO was accompanied by significantly better vision during the first four weeks (2.3 (IQR 0.75) vs. 2.6 (IQR 0.33); p = 0.006). Moreover, the spot sign seems to be a prognostic factor for developing secondary retinal ischemia (8 (100%) vs. 0 (0%); p = 0.036). A retrobulbar spot sign seems to be a negative prognostic factor and is associated with secondary retinal ischemia, whereas a p-MLM sign is a somewhat positive prognostic factor for visual acuity.

Endovascular surgery in the field of ophthalmology

In this article, we provide an overview of the current perspectives on endovascular surgery in ophthalmology, including a description of the various approaches, recent clinical results and future prospects. Experimental studies of endovascular surgery in ophthalmology started in the 1980s; since then, a considerable amount of research has been done to develop the procedure for clinical use. During the past two decades endovascular surgery has been performed on eyes with retinal vascular disorders, including central retinal vein occlusion and central retinal artery occlusion. The first endovascular surgery on human eyes was performed in 1998 on a patient with central retinal vein occlusion (CRVO). The most recent techniques used in retinal endovascular surgery involve manual injection of liquid agents such as tissue plasminogen activator into major retinal vessels using a 47 or 48-gauge micro-needle. New technology using a bimanual procedure and digitally assisted vitrectomy systems enables surgeons to perform this delicate procedure more effectively. Recent results reported from a number of researchers corroborate the effectiveness of the procedure. Endovascular surgery is one of the latest techniques in the field of ophthalmology and has garnered significant interest from vitreoretinal surgeons. However, it is also at the limit of what surgeons are able to accomplish with manual precision. There is still much to learn and improve to maximize the potential of this approach. The combination of skills as a surgeon, sound science, objective clinical evidence and cutting edge technology will lead to improvements in this field.

Retinal oedema in central retinal artery occlusion develops as a function of time

PURPOSE

Time is the key criterion in the management of non-arteritic central retinal artery occlusion (NA-CRAO). However, the precise onset of vision loss is often difficult to determine. This study aimed to evaluate the temporal changes of retinal thickness in acute NA-CRAO and the potential of this parameter to be used as a surrogate marker to estimate the onset of retinal ischaemia.

METHODS

Optical coherence tomography was used to continuously assess retinal thickness and oedema progression rate in six porcine eyes. Additionally, a retrospective analysis of 12 patients with acute NA-CRAO was performed to determine association strength and progression rate between retinal thickness and onset of ischaemia. All Optical coherence tomography (OCT) scans (pigs and NA-CRAO patients) were performed within an ischaemic time frame of up to 9 hr.

RESULTS

Retinal oedema progression rate in pigs was 25.32 µm/hr [CI 95%: 24.24-26.40 µm/hr]. Retrospective analysis of the patients revealed a strong correlation between retinal oedema and duration of ischaemia (Spearman's rho = 0.77, p = 0.004) with an estimated progression rate of 10.02 µm/hr [CI 95%: 3.30-16.74 µm/hr].

CONCLUSION

Retinal thickness increases with oedema formation, and ischaemia onset is strongly correlated with this structural biomarker in both, pigs and NA-CRAO patients. Prospective clinical trials will have to determine the clinical feasibility of retinal thickness measurements as a biomarker to support clinical management of NA-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 Associated with Carotid Artery Occlusion

Sudden, painless vision loss in patients with stroke risk factors is suspect for central retinal artery occlusion (CRAO), an ophthalmic emergency that in addition to ocular treatment warrants a thorough neurologic and vascular evaluation. In addition to the high risk of concurrent stroke, carotid artery stenosis and occlusion is often overlooked during the initial evaluation. Here we report a case of CRAO with concurrent ipsilateral complete left internal carotid artery (ICA) occlusion and right ICA critical narrowing, dissection and pseudoaneurysm, which subsequently improved with prompt hyperbaric oxygen therapy.

Acute retinal arterial ischemia

Acute retinal arterial ischemia, which includes transient monocular vision loss (TMVL), branch retinal artery occlusion (BRAO), central retinal artery occlusion (CRAO) and ophthalmic artery occlusion (OAO), is most commonly the consequence of an embolic phenomenon from the ipsilateral carotid artery, heart or aortic arch, leading to partial or complete occlusion of the central retinal artery (CRA) or its branches. Acute retinal arterial ischemia is the ocular equivalent of acute cerebral ischemia and is an ophthalmic and medical emergency. Patients with acute retinal arterial ischemia are at a high risk of having further vascular events, such as subsequent strokes and myocardial infarctions (MIs). Therefore, prompt diagnosis and urgent referral to appropriate specialists and centers is necessary for further work-up (such as brain magnetic resonance imaging with diffusion weighted imaging, vascular imaging, and cardiac monitoring and imaging) and potential treatment of an urgent etiology (e.g., carotid dissection or critical carotid artery stenosis). Since there are no proven, effective treatments to improve visual outcome following permanent retinal arterial ischemia (central or branch retinal artery occlusion), treatment must focus on secondary prevention measures to decrease the likelihood of subsequent ischemic events.

Intravenous thrombolysis in acute central retinal artery occlusion - A prospective interventional case series

BACKGROUND

No evidence-based therapy exists for non-arteritic central retinal artery occlusion (NA-CRAO). Retinal ischemic tolerance is low; irreversible damage occurs within four hours of experimental NA-CRAO. In previous randomized trials evaluating intra-arterial or intravenous thrombolysis (IVT) in NA-CRAO, only one patient was treated this early. In December 2013, the Departments of Neurology & Stroke and Ophthalmology at University Hospital Tuebingen, Germany, decided to treat patients using IVT within 4.5 hours of NA-CRAO, the therapeutic window established for ischemic stroke.

MATERIALS AND METHODS

Consecutive NA-CRAO patients with severe visual loss received IVT after exclusion of intracranial hemorrhage. Follow-up was conducted at day 5 (d5) and day 30 (d30). Visual outcomes were compared to the conservative standard treatment (CST) arm of the EAGLE-trial.

RESULTS

Until August 2016, 20 patients received IVT within 4.5 hours after NA-CRAO with a median onset-to-treatment time of 210 minutes (IQR 120-240). Visual acuity improved from baseline mean logarithm of the minimum angle of resolution 2.46±0.33 (SD) (light perception) to 1.52±1.09 (Snellen equivalent: 6/200) at d5 (p = 0.002) and 1.60±1.08 (Snellen equivalent: 6/240) at d30. Compared to the EAGLE CST-arm, functional recovery to reading ability occurred more frequently after IVT: 6/20 (30%) versus 1/39 (3%) at d5 (p = 0.005) and at d30 5/20 (25%) versus 2/37 (5%) (p = 0.045). Two patients experienced serious adverse events (one angioedema and one bleeding from an abdominal aortic aneurysm) but recovered without sequelae.

CONCLUSIONS

IVT within 4.5 hours after symptom onset may represent an effective treatment of NA-CRAO. Randomized trials are warranted to evaluate efficacy and safety of early IVT in acute NA-CRAO.

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.

Update on the Management of Central Retinal Artery Occlusion

Central retinal artery occlusion (CRAO) is caused by partial or complete occlusion of the central retinal artery, most commonly by an embolus from the ipsilateral carotid artery, aortic arch, or heart, and is the ocular equivalent of an acute cerebral ischemic event. The risk factors for a CRAO and acute cerebral ischemia are very similar, if not identical. Because no current therapeutic intervention has been shown to improve visual outcomes compared with the natural history of CRAO, management of CRAO should be focused on secondary prevention of vascular events, such as cerebral ischemia, myocardial infarction, and cardiovascular death.

Central Retinal Artery Occlusion: Acute Management and Treatment

PURPOSE OF REVIEW

This review will seek to answer if advances in ophthalmic imaging and evolution of treatment modalities have shed further light on the epidemiology, pathophysiology, diagnosis, and acute management of acute CRAO.

RECENT FINDINGS

Imaging characteristics of acute CRAO have been further characterized with the use of fluorescein angiography, optical coherence tomography (OCT), OCT-angiography, and indocyanine-green angiography. Layer segmentation of OCT imaging has found inner retinal layer hyper-reflectivity to be a common finding in acute CRAO. Non-invasive therapies, fibrinolytic delivery, and surgical interventions for acute CRAO have been further evaluated as potential management tools.

SUMMARY

A large body of literature reports very inconsistent treatment success with a wide variety of modalities. Currently, there is no clear evidence supporting the use of fibrinolytics in acute CRAO. Large, multicenter, randomized control trials are necessary to elucidate the role of the various acute treatment options in the management of CRAO.

Management of acute central retinal artery occlusion: Intravenous thrombolysis is feasible and safe

Background

Although acute central retinal artery occlusion is as a stroke in the carotid territory (retinal artery), its management remains controversial. The aim of this study was to assess the feasibility and safety of intravenous thrombolysis delivered within 6 h of central retinal artery occlusion in French stroke units.

Methods

We performed a retrospective analysis of patients treated with intravenous alteplase (recombinant tissue-plasminogen activator), based on stroke units thrombolysis registers from June 2005 to June 2015, and we selected those who had acute central retinal artery occlusion. The feasibility was assessed by the ratio of patients that had received intravenous alteplase within 6 h after central retinal artery occlusion onset among those who had been admitted to the same hospital for acute central retinal artery occlusion. All adverse events were documented.

Results

Thirty patients were included. Visual acuity before treatment was limited to “hand motion”, or worse, in 90% of the cases. The mean onset-to-needle time was 273 min. The individuals treated with intravenous alteplase for central retinal artery occlusion represented 10.2% of all of the patients hospitalized for central retinal artery occlusion in 2013 and 2014. We observed one occurrence of major bleeding, a symptomatic intracerebral hemorrhage.

Conclusion

When applied early on, intravenous thrombolysis appears to be feasible and safe, provided that contraindications are given due consideration. Whether intravenous thrombolysis is more effective than conservative therapy remains to be determined. In order to conduct a well-designed prospective randomized control trial, an organized network should be in place.

No-Reflow Phenomenon in Central Retinal Artery Occlusion: Incidence, Risk Factors, and Clinical Implications

PURPOSE

To investigate the incidence and risk factors of the no-reflow phenomenon in central retinal artery occlusion (CRAO) patients and to determine its effects on visual and anatomic outcomes.

METHODS

In 102 eyes with CRAO in which arterial recanalization was obtained within 1 week from baseline, fluorescein angiography images obtained at baseline and 1 week were retrospectively reviewed. The no-reflow phenomenon in the retina was defined as macular capillary nonperfusion following arterial recanalization on fluorescein angiographs. We investigated the incidence and risk factors for the no-reflow phenomenon and compared the anatomical and visual outcomes between eyes with and without the phenomenon.

RESULTS

Among the 102 CRAO eyes with arterial recanalization, 39 exhibited the no-reflow phenomenon, resulting in an incidence of 38.2%. The incidence among the eyes with treatment-induced and spontaneous recanalization was 43.4% and 15.8%, respectively, and it increased with the CRAO stage. CRAO stage and increased central macular thickness were risk factors for the phenomenon, with an odds ratio of 4.47 [95% confidence interval (CI), 1.19-16.8; P = 0.027] and 1.69 (95% CI, 1.12-2.55; P = 0.012) per 100-μm increase, respectively. The visual outcome was significantly poorer and retinal atrophy and photoreceptor disruption was greater in eyes with the no-reflow phenomenon than in those without.

CONCLUSIONS

The no-reflow phenomenon may occur after arterial recanalization in approximately one-third of CRAO patients and can affect anatomical and visual outcomes. This phenomenon may provide an additional explanation regarding the permanent retinal damage and vision loss in eyes with CRAO.

Retrobulbar Spot Sign Predicts Thrombolytic Treatment Effects and Etiology in Central Retinal Artery Occlusion

BACKGROUND AND PURPOSE

Transorbital sonography may help establish diagnosis of central retinal artery occlusion (CRAO). Next to Doppler sonographic proof of CRAO, an intra-arterial spot sign can be detected in some cases. We hypothesized that it reflects calcified components. It may be associated with embolization from atherosclerotic plaques and may negatively influence thrombolysis.

METHODS

Prospective monocenter study of 46 patients with ophthalmologically confirmed CRAO. Systemic tissue-type plasminogen activator thrombolysis was performed when appropriate. All patients received etiologic workup.

RESULTS

CRAO was confirmed by Doppler in all patients. Fifty-nine percent of patients with arterio-arterial embolization were spot sign-positive compared with 20% from cardiac source (P<0.05) and none with vasculitis. Eleven patients underwent thrombolysis. Clinically relevant visual improvement was only found in absence of a spot sign (P<0.05).

CONCLUSIONS

Transbulbar ultrasound is valuable for initial diagnosis and diagnostic workup of CRAO. In the light of inconsistent results of previous thrombolysis trials, ultrasound may identify patients more likely to benefit from thrombolytic treatment.

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.

Low endogenous recanalization in embolic central retinal artery occlusion--the retrobulbar "spot sign"

BACKGROUND AND PURPOSE

Central retinal artery occlusion (CRAO) is most often indirectly diagnosed by lack of retinal perfusion. Direct embolus characterization may help to understand the natural course and low response to treatment. In a previous study we identified a hyperechoic signal within the optic nerve and in the central retinal artery ("spot sign").

METHODS

In this study we performed a follow-up investigation in 7 patients with CRAO and positive spot sign indicating the embolic cause of the occlusion after a median interval of 17 months (range 11-38 months) using a battery of tests (ocular color-coded sonography, optic coherence tomography [OCT], fundoscopy, amongst others).

RESULTS

The spot sign persisted in all patients, none had high-grade internal carotid artery stenosis, stroke or transient ischemic attacks. Four patients were completely blind, 3 patients were able to recognize hand movements. OCT demonstrated retinal atrophy, and fundoscopy revealed only minimal arterial perfusion.

CONCLUSIONS

The hyperechoic spot sign may be an important predictive prognostic marker for persistent loss of vision. Its persistence may indicate calcified or cholesterol emboli and may explain the low therapeutic success rate to thrombolysis. Further studies on their origin and significance in atherosclerotic disease are warranted.

The central retinal artery occlusion in the right eye followed by a branch retinal artery occlusion in the left eye four days later

A 65-year-old woman was admitted to our clinic with complaints of sudden, painless, decrease in vision, and sectoral visual field defect in the left eye and later presented to our clinic again with a history of sudden loss of vision in her right eye. In this case study we reported that the patient had branch retinal artery occlusion (BRAO) in the left eye and at the same time progressing central retinal artery occlusion (CRAO) in the right eye.

Acute central retinal artery occlusion associated with livedoid vasculopathy: a variant of Sneddon's syndrome

Livedoid vasculopathy (LV) is characterized by a long history of ulceration of the feet and legs and histopathology indicating a thrombotic process. We report a case of acute central retinal artery occlusion in a 32-year-old woman who had LV. She showed no discernible laboratory abnormalities such as antiphospholipid antibodies and no history of cerebrovascular accidents. Attempted intra-arterial thrombolysis showed no effect in restoring retinal arterial perfusion or vision. The central retinal artery occlusion accompanied by LV in this case could be regarded as a variant form of Sneddon's syndrome, which is characterized by livedo reticularis and cerebrovascular accidents.

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.

Treatment options for central retinal artery occlusion

OPINION STATEMENT

Central retinal artery occlusion (CRAO) is an ocular emergency and is the ocular analogue of cerebral stroke. It results in profound, usually monocular vision loss, and is associated with significant functional morbidity. The risk factors for CRAO are the same atherosclerotic risk factors as for stroke and heart disease. As such, individuals with CRAO may be at risk of ischemic end organ damage such as a cerebral stroke. Therefore, the management of CRAO is not only to restore vision, but at the same time to manage risk factors that may lead to other vascular conditions. There are a number of therapies that has been used in the treatment of CRAO in the past. These include carbogen inhalation, acetazolamide infusion, ocular massage and paracentesis, as well as various vasodilators such as intravenous glyceryl trinitrate. None of these "standard agents" have been shown to alter the natural history of disease definitively. There has been recent interest shown in the use of thrombolytic therapy, delivered either intravenously or intra-arterially by direct catheterisation of the ophthalmic artery. Whilst a number of observational series have shown that the recovery of vision can be quite dramatic, two recent randomised controlled trials have not demonstrated efficacy. On the contrary, intra-arterial delivery of thrombolytic may result in an increased risk of intracranial and systemic haemorrhage, while the intravenous use of tissue plasminogen activator (tPA) was not shown to be efficacious within 24 h of symptom onset. Nevertheless, both of these studies have shown one thing in common, and that is for treatment to be effective in CRAO, it must be deployed within a short time window, probably within 6 h of symptom onset. Therefore, while CRAO is a disease that does not have a treatment, nevertheless it needs to follow the same principles of treatment as any other vascular end organ ischaemic disease. That is, to attempt to reperfuse ischemic tissue as quickly as possible and to institute secondary prevention early.

Innervation pattern of the preocular human central retinal artery

The central retinal artery (CRA) is the main vessel for inner retinal oxygen and nutrition supply. While the intraocular branches lack autonomic innervation, the innervation pattern of the extra-ocular part of this vessel along its course within the optic nerve is poorly investigated. This part however is essential for maintenance of retinal blood supply, in physiological and pathological conditions. Therefore, the aim of this study was the characterization of the autonomic innervation of the preocular CRA in humans with morphological methods. Meeting the Declaration of Helsinki, eyes of body or cornea donors were processed for single or double immunohistochemistry against tyrosine hydroxilase (TH), dopamine-β-hydroxylase (DBH), choline acetyl-transferase (ChAT), vesicular acetylcholine transporter (VAChT), neuronal nitric oxide synthase (nNOS), calcitonin gene-related peptide (CGRP), substance P (SP), vasoactive intestinal polypeptide (VIP), and cytochemistry for NADPH-diaphorase (NADPH-d). For documentation, light-, fluorescence-, and confocal laser-scanning microscopy were used. TH and DBH immunoreactive nerve fibres were detected in the CRA vessel wall, although a distinct perivascular plexus was missing. Further, nerve fibres immunoreactive for ChAT and VAChT were found, while CGRP, SP, and VIP were not detected. NADPH-d staining revealed scattered nerve fibres in the adventitia of the CRA and in close vicinity; however, nNOS-immunostaining could not confirm this finding. The CRA receives adrenergic and cholinergic innervations, indicating sympathetic and parasympathetic components, respectively. Remarkably, a peptidergic primary afferent innervation was missing. Since clinical results suggest an autoregulation of intraretinal vessels, further studies are needed to clarify the impact of CRA innervation for retinal perfusion.