Intra-Arterial Tissue Plasminogen Activator for Central Retinal Artery Occlusion

A telemedicine-enabled intravenous thrombolytic treatment pathway for patients with hyperacute non-arteritic central retinal artery occlusion

Purpose

To describe the visual acuity (VA) outcomes from a telemedicine-enabled pathway allowing for rapid diagnosis and administration of intravenous (IV) thrombolytic treatment for non-arteritic central retinal artery occlusion (naCRAO) within 4.5 hours (4.5 h) of visual loss.

Design

Retrospective observational case series.

Methods

Setting: A large managed healthcare consortium.Patient Population: Eighty-five patients with naCRAO and vision loss for less than 4.5 h presenting between 2021 and 2023. Thirty-five patients received IV thrombolytic therapy and 50 patients were closely observed.Intervention: A collaborative telemedicine-enabled pathway employing fundus photography was previously established by Ophthalmology, Emergency Medicine, and Stroke services to rapidly evaluate and manage patients presenting with acute painless monocular vision loss and allow for administration of IV tenecteplase (0.25 mg/kg) for eligible consenting patients diagnosed with naCRAO within 4.5 h. Retrospective chart review was conducted to collect data on demographics, vascular risk factors, clinical features, VA outcomes, and adverse events. Comparison was made between patients who received intravenous thrombolysis and those who were observed.Main Outcome Measures: Improvement in VA of at least 0.3 logarithm of the minimum angle of resolution (logMAR) and/or from 20/200 or worse to 20/100 or better.

Results

A greater percentage of patients in the treated group had VA improvement of ≥0.3 logMAR (54.3 % vs 28 %, p = .014), and a greater percentage of patients in the untreated group had VA worsening of ≥0.3 logMAR (30 % vs 5.7 %, p = .006). Twice the percentage of treated versus untreated patients had improved VA from 20/200 or worse to 20/100 or better, but this difference was not statistically significant (20 % vs 10 %, p = .192). There was a significantly shorter mean time to treatment for those patients who had VA improvement from 20/200 or worse to 20/100 or better compared to those who did not (118 versus 171 min, p = .031). Two patients experienced intracranial bleeding after IV thrombolysis.

Conclusions

The evaluation and treatment of hyperacute naCRAO is possible on a large scale via an integrated telemedicine-enabled approach utilizing fundus photography. The use of IV thrombolytic was associated with better VA outcomes compared to observation alone. Prospective randomized controlled trials are needed to confirm these findings and determine optimal management.

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.

Successful Treatment of Central Retinal Artery Occlusion With Tissue Plasminogen Activator Followed by Recurrent Retinal Ischemia

Purpose: To describe the use of intra-arterial tissue plasminogen activator (tPA) to treat central retinal artery occlusion (CRAO). Methods: A case and its findings were analyzed. Results: A 45-year-old man diagnosed with a CRAO and had cerebral angiography and treatment with intra-arterial tPA. After treatment, follow-up included optical coherence tomography (OCT), fundus photography, fluorescein angiography, and OCT angiography. The visual acuity (VA) improved from hand motions to 20/30 immediately after fibrinolysis. A vascular occlusion event the next day resulted in a decrease in VA to 20/400. After initiation of dual antiplatelet therapy, the patient's VA improved to 20/20. As the retina recovered, the evolution of retinal ischemic changes to a finding similar to paracentral acute middle maculopathy was seen on imaging. Conclusions: This is the first report describing a patient safely started on dual antiplatelet therapy that led to vision improvement after initial treatment with intra-arterial tPA for a CRAO resulted in recurrent vision loss.

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.

Nationwide Incidence and Trends in Central Retinal Arterial Occlusion Management: A 5000-Patient Analysis

Central retinal artery occlusion (CRAO) is a rare and visually debilitating vascular condition characterized by sudden and severe vision loss. CRAO is a compelling target for intravenous alteplase (tPA) and endovascular mechanical thrombectomy (MT) due to pathophysiological similarities with acute ischemic stroke; however, the utility of these interventions in CRAO remains dubious due to limited sample sizes and potential risks. To assess usage and outcomes of tPA and MT in CRAO, we queried the National Inpatient Sample database using International Classification of Disease, Ninth and Tenth edition for patients with CRAO and acute ischemic stroke between 2010 and 2019. Our cohort of 5009 CRAO patients were younger with higher rates of obesity, hypertension, long-term anticoagulant use, and tobacco use compared to acute ischemic stroke patients. CRAO patients had lower rates of tPA administration (3.41% vs 6.21%) and endovascular MT (0.38% vs 1.31%) but fewer complications, including deep vein thrombosis, pneumonia, urinary tract infection, acute kidney injury, and acute myocardial infarction (all P < 0.01). CRAO patients had lower rates of poor functional outcome (31.74% vs 58.1%) and in-hospital mortality (1.2% vs 5.64%), but higher rates of profound blindness (9.24% vs 0.58%). A multivariate regression showed no relationship between tPA and MT and profound blindness, although the limited sample size of patients receiving interventions may have contributed to this apparent insignificance. Further investigation of larger patient cohorts and alternative treatment modalities could provide valuable insights for revascularization therapies in CRAO to optimize visual restoration and clinical outcomes.

A Remote Consult Retinal Artery Occlusion Diagnostic Protocol

PURPOSE

To report a novel protocol for diagnosis of retinal artery occlusions at the point of care using OCT and a remote consult model.

DESIGN

Retrospective case series and evaluation of a diagnostic test or technology.

PARTICIPANTS

Adult patients who presented with painless monocular vision loss and were diagnosed with a nonarteritic retinal artery occlusion.

METHODS

OCT machines were placed in the stroke center or emergency department at 3 hospitals within our health system. Patients who presented with painless monocular vision loss were evaluated by the stroke neurology service and an OCT was acquired. The images were interpreted remotely by the retina service. An in-house ophthalmology consult was not required to make the final treatment decision. Eligible patients were treated with intra-arterial tissue plasminogen activator (IA-tPA). Patients were followed by ophthalmology during their admission when an in-house consultation service was available or otherwise evaluated immediately after discharge.

MAIN OUTCOME MEASURES

Visual acuity (VA) before and after treatment with IA-tPA; time from last known well (LKW) to treatment; and time from presentation to treatment.

RESULTS

In the first 18 months since the protocol went live, 59 patients were evaluated. Twenty-five patients (42%) had a confirmed retinal artery occlusion based on OCT and follow-up examination. Ten patients were eligible for treatment, and 9 patients received treatment with IA-tPA. There was a statistically significant improvement in mean VA from logarithm of the minimum angle of resolution (logMAR) 2.14 to logMAR 0.7 within 24 hours after treatment (P = 0.0001) and logMAR 1.04 after 4 weeks (P = 0.01). Clinically significant improvement was noted in 66% of patients within 24 hours and maintained through 1 month in 56% of all treated patients. The mean time to treatment from LKW was 543 minutes and from presentation at the stroke center was 146 minutes.

CONCLUSIONS

We report the successful implementation of a remote consult protocol using point-of-care automated OCT. This novel paradigm demonstrates the potential utility of remote consult services for the diagnosis of time-sensitive ophthalmic emergencies.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found after the references.

Retinal Artery Reperfusion After Translumenal YAG Laser Embolysis in a Case of Branch Retinal Artery Occlusion

Purpose: To present a potential treatment for embolic branch retinal artery occlusion (BRAO). Methods: A case and its findings were analyzed. Results: A 75-year-old man with a 5-day history of an acute superior visual field defect in the right eye was found to have a BRAO secondary to a Hollenhorst plaque and was treated with translumenal YAG laser embolysis. Reperfusion of the retinal artery was observed on dislodging the Hollenhorst plaque, and improvements were seen in the patient's superior visual field defect. Conclusions: Translumenal YAG laser embolysis could potentially reverse ischemia secondary to embolic RAOs. This case report and the current literature cited suggest a rationale for treatment and supports further study of this technique.

Thrombolytic Therapy for Central Retinal Artery Occlusion in an Academic Multi-Site Stroke Centre

Central retinal artery occlusion (CRAO) is a subtype of acute ischaemic stroke leading to severe visual loss. A recent American Heart Association scientific statement proposed time-windows for thrombolysis in CRAO similar to acute ischaemic cerebral strokes. We aimed to review our academic multi-site stroke centre experience with intravenous (IVT) and intra-arterial thrombolysis (IAT) in CRAO between 1997 and 2022. Demographic, clinical characteristics, thrombolysis timeline, concurrent therapies, complications, and 3-month follow-up visual acuity (VA) were collected. The thrombolysed cohort follow-up VA was compared with an age, gender and baseline VA matched cohort of CRAO patients that received conservative therapies. Thrombolytic therapy was administered to 3.55% (n = 20) of CRAO admissions; 13 IVT (mean age 68, 61.5% male, 12 alteplase and 1 tenecteplase, all embolic aetiology, 1 CRAO mimic) and 7 IAT (mean age 55, 85.7% male, 3 post-operative and 3 embolic). Additional conservative CRAO-targeting therapies was received by 60%. The median time from onset of visual loss to IVT was 158 minutes (range 67-260). Improvement by at least two Snellen lines was achieved by 25% with 12.5% improving to 20/100 or better. Intracranial haemorrhage post IVT occurred in 1/13 (7.6%). The median time from onset of visual loss to IAT was 335 minutes. Improvement by at least two Snellen lines was achieved by 42%. No difference in 3-month VA was noted between patients that received thrombolysis, either alone (n = 8) or combined with other therapies, and those that received conservative therapies. Our results suggest that the management of acute CRAO remains heterogeneous. The lack of obvious benefit of thrombolysis in our small series supports the need for randomizsd clinical trials comparing thrombolysis to placebo to guide hyperacute CRAO management.

Thrombolysis for central retinal artery occlusion: An individual participant-level meta-analysis

BACKGROUND

Whether thrombolysis improves outcomes in non-arteritic central retinal artery occlusion (naCRAO) is uncertain. We aimed to evaluate the rate of visual recovery after intra-venous thrombolysis (IVT) or intra-arterial thrombolysis (IAT) administration of tissue plasminogen activator (tPA) or urokinase among patients with naCRAO and explore the parameters affecting the final visual acuity (VA).

AIM

We systematically searched six databases. Logarithm of the minimum angle of resolution (logMAR) and VA of ⩾20/100 were used to quantify visual recovery. To explore the role of other factors on visual recovery, we defined two models for studies with aggregated data (designs 1 and 2) and 16 models for individual participant data (IPD, models 1-16).

SUMMARY OF REVIEW

We included data from 771 patients out of 72 publications in nine languages. Visual improvement for ⩾0.3 logMAR was reported in 74.3% of patients who received IVT-tPA within 4.5 h (CI: 60.9-86.0%; unadjusted rate: 73.2%) and 60.0% of those who received IAT-tPA within 24 h (CI: 49.1-70.5%; unadjusted rate: 59.6%). VA of ⩾20/100 was observed among 39.0% of patients after IVT-tPA within 4.5 h and 21.9% of those with IAT-tPA within 24 h. IPD models highlighted the association between improved visual outcomes and VA at presentation, at least 2 weeks follow-up before reporting the final VA, antiplatelet therapy, and shorter symptom onset to thrombolysis window.

CONCLUSION

Early thrombolytic therapy with tPA is associated with enhanced visual recovery in naCRAO. Future studies should refine the optimum time window for thrombolysis in naCRAO.

Retinal Findings and Cardiovascular Risk: Prognostic Conditions, Novel Biomarkers, and Emerging Image Analysis Techniques

Many retinal diseases and imaging findings have pathophysiologic underpinnings in the function of the cardiovascular system. Myriad retinal conditions, new imaging biomarkers, and novel image analysis techniques have been investigated for their association with future cardiovascular risk or utility in cardiovascular risk prognostication. An intensive literature search was performed to identify relevant articles indexed in PubMed, Scopus, and Google Scholar for a targeted narrative review. This review investigates the literature on specific retinal disease states, such as retinal arterial and venous occlusions and cotton wool spots, that portend significantly increased risk of future cardiovascular events, such as stroke or myocardial infarction, and the implications for personalized patient counseling. Furthermore, conditions diagnosed primarily through retinal bioimaging, such as paracentral acute middle maculopathy and the newly discovered entity known as a retinal ischemic perivascular lesion, may be associated with future incident cardiovascular morbidity and are also discussed. As ever-more-sophisticated imaging biomarkers and analysis techniques are developed, the review concludes with a focused analysis of optical coherence tomography and optical coherence tomography angiography biomarkers under investigation for potential value in prognostication and personalized therapy in cardiovascular disease.

Retinal stroke: research models, targets and experimental drugs

INTRODUCTION

Retinal artery occlusion (RAO), often caused by a microembolus and resulting in inner retinal ischemia, could be considered as the retinal analog to cerebral stroke. Although several therapeutic targets have been suggested in animal models of retinal ischemia and several potential treatments have been evaluated on small series of patients, central retinal artery occlusion (CRAO) is still rarely treatable in clinical practice.

AREAS COVERED

Here, we review several animal models of RAO, including increased intraocular pressure, laser, vasoconstriction, embolization and clamp. We also review the pathogenic mechanisms that contribute to cell death cascades during ischemia, and the therapeutic strategies targeting these events. These strategies aim to restore blood flow by fibrinolysis, increase the oxygen or glucose supply, decrease the energy demands, restrict ionic leak fluxes or reduce the detrimental effects of glutamate, calcium and free radicals. The current literature suggests that tPA treatment could be effective for CRAO.

EXPERT OPINION

Eye care professionals must make a rapid and accurate diagnosis and immediately refer patients with acute retinal stroke to specialized centers. CRAO management should also be facilitated by developing local networks to encourage collaboration among ophthalmologists, retina specialists and stroke neurologists.

Paracentral acute middle maculopathy presenting as a sign of impending central retinal artery occlusion: a case report

BACKGROUND

To report a case of paracentral acute middle maculopathy (PAMM) that progressed to central retinal artery occlusion (CRAO) on spectral domain-optical coherence tomography (SD-OCT).

CASE PRESENTATION

A 63-year-old male presented with a paracentral scotoma that began several days ago. His past medical history consisted of third-degree atrioventricular heart block requiring a pacemaker. Giant cell arteritis was unlikely given the patient's labs, demographics and review of systems. SD-OCT revealed a characteristic hyperreflective band in the inner nuclear layer consistent with PAMM in his left eye. Fluorescein angiography was obtained and was unremarkable. Five days later, the patient developed no light perception in the left eye. SD-OCT showed a diffuse inner retinal hyperreflectivity consistent with CRAO.

CONCLUSION

PAMM can be a harbinger event for complete CRAO. Complete stroke evaluation should be performed to prevent a cerebrovascular event or progression to complete blindness in the involved eye.

Description of a Nonhuman Primate Model of Retinal Ischemia/Reperfusion Injury

Purpose

To establish an inducible model of retinal ischemia/reperfusion injury (RI/RI) in nonhuman primates (NHPs) to improve our understanding of the disease conditions and evaluate treatment interventions in humans.

Methods

We cannulated the right eye of rhesus macaques with a needle attached to a normal saline solution reservoir at up to 1.9 m above the eye level that resulted in high intraocular pressure of over 100 mm Hg for 90 minutes. Retinal morphology and function were monitored before and after RI/RI over two months by fundus photography, optical coherence tomography, electroretinography, and visual evoked potential. Terminal experiments involved immunostaining for retinal ganglion cell marker Brn3a, glial fibrillary acidic protein, and quantitative polymerase chain reaction to assess retinal inflammatory biomarkers.

Results

We observed significant and progressive declines in retinal and retinal nerve fiber layer thickness in the affected eye after RI/RI. We noted significant reductions in amplitudes of electroretinography a-wave, b-wave, and visual evoked potential N2-P2, with minimal recovery at 63 days after injury. Terminal experiments conducted two months after injury revealed ∼73% loss of retinal ganglion cells and a fivefold increase in glial fibrillary acid protein immunofluorescence intensity compared to the uninjured eyes. We observed marked increases in tumor necrosis factor-alpha, interferon-gamma, interleukin-1beta, and inducible nitric oxide synthase in the injured retinas.

Conclusions

The results demonstrated that the pathophysiology observed in the NHP model of RI/RI is comparable to that of human diseases and suggest that the NHP model may serve as a valuable tool for translating interventions into viable treatment approaches.

Translational Relevance

The model serves as a useful platform to study potential interventions and treatments for RI/RI or blinding retinal diseases.

Intra-arterial Thrombolysis for Acute Retinal Ischemia: A Retrospective, Observational, Cohort Study

BACKGROUND

To determine whether intra-arterial thrombolysis (IAT) within 16 hours after the onset of symptoms is feasible and associated with better visual outcomes in patients with acute retinal ischemia (ARI).

METHODS

The retrospective cohort study was performed from January 2014 to December 2021 in the Xuanwu Hospital of Capital Medical University. Patients with ARI who initially presented visual acuity of 20/100 or worse were screened in the study. Visual end points were evaluated at one week and at final visit after treatment. Serious adverse events were recorded during operation and within 1 week after IAT treatment.

RESULTS

The amount of clinically significant visual improvement (≥0.3 logarithm of the minimum angle of resolution) in the IAT group was significantly higher than that in the conservative treatment group at one week after the treatment (47.8% vs 16.7%; P = 0.014) and at final visit (52.2% vs 20%; P = 0.014). After controlling confounding factors, ARI treatment was the only factor significantly associated with the amount of clinically significant visual improvement (OR, 4.364; 95 CI, 1.298-14.667; P = 0.017). A patient (4.3%) experienced retinal hemorrhage without symptom within 1 week after IAT treatment. No patients experienced new symptomatic cerebral infarction, intracranial hemorrhage, TIA, artery dissection, vascular perforation, and distal embolization during operation and within 1 week after IAT treatment.

CONCLUSIONS

IAT may be associated with better visual improvement within 16 hours after the onset of symptoms. Besides, IAT is feasible and associated with a low risk of periprocedural complications for ARI. This study will aid in feasibility testing and sample size calculations in advance of future, fully-powered efficacy studies for ARI.

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.

A review of the management of central retinal artery occlusion

Central retinal artery occlusion (CRAO), the ocular analog of a cerebral stroke, is an ophthalmic emergency. The visual prognosis for overall spontaneous visual recovery in CRAO is low. Furthermore, the risk of future ischemic heart disease and cerebral stroke is increased due to the underlying atherosclerotic risk factors. There is currently no guideline-endorsed treatment for CRAO. This review will describe the anatomy, pathophysiology, epidemiology, and clinical features of CRAO, and investigate the current and future management strategies.

Efficacy of Intra-Arterial Thrombolysis for Acute Central Retinal Artery Occlusion: A Meta-Analysis

INTRODUCTION

The best management strategy still remains strong controversy for acute nonarteritic central retinal artery occlusion (CRAO). We thus performed a meta-analysis to determine the efficacy of intra-arterial thrombolysis (IAT) for visual improvement according to different times from symptom onset.

METHODS

We searched EMBASE, PubMed, and Web of Science for relevant studies assessing efficiency of IAT in patients with CRAO compared with standard therapy. Fixed-effects and random-effects models were performed.

RESULTS

Five eligible studies including 459 patients with acute CRAO were pooled in the meta-analysis. In all, 219 (47.7%) received IAT, and the mean time from symptom onset to IAT was 13 h. The pooled analysis demonstrates odds ratio (OR) for the procedure of IAT and any visual improvement to be 1.520 (95% confidence intervals [CIs] 1.258-1.837; p < 0.001). Subgroup analyses further indicated that the CRAO patients who received IAT achieved any visual improvement more easily within 6 h from symptom onset (OR = 1.703, 95% CI 1.219-2.381; p = 0.002), but not those beyond 6 h (OR = 1.260, 95% CI 0.973-1.632; p = 0.080).

CONCLUSION

Our meta-analysis of available published data supports IAT to be an alternative treatment option for CRAO patients within 6 h from symptom onset.