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

Antithrombotic use in retinal artery occlusion: A narrative review

Retinal artery occlusion (RAO) is a critical ophthalmic emergency with a high risk of significant visual impairment. While traditional treatment aims to promptly restore blood flow to the retina, recent research has investigated the potential benefits of anticoagulation therapy for managing this condition. This paper reviews current literature and clinical trials investigating the efficacy and safety of anticoagulant and antiplatelet therapies, such as systemic heparinization and direct oral anticoagulants and aspirin, in treating RAO. The mechanism of action involves preventing thrombus propagation and platelet aggregation to promote microvascular circulation, potentially mitigating ischemic damage and improving visual outcomes. However, controversies exist regarding the optimal timing, duration, and selection of antithrombotic agents due to the risk of hemorrhagic complications. Further large-scale prospective studies are warranted to establish evidence-based guidelines for incorporating antithrombotic into the standard management of RAO. This paper underscores the evolving landscape of antithrombotic therapy as a promising adjunctive treatment strategy in the management of 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.

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.

Implementation of a retinal stroke-code protocol results in visual recovery in patients receiving reperfusion therapies

INTRODUCTION

Reperfusion therapies represent promising treatments for patients with Central Retinal Artery Occlusion (CRAO), but access is limited due to low incidence and lack of protocols. We aimed to describe the benefit of implementing a Retinal Stroke-Code protocol regarding access to reperfusion, visual acuity and aetiological assessment.

PATIENTS AND METHODS

Prospective cohort study performed at a Comprehensive Stroke Centre. Criteria for activation were sudden monocular, painless vision loss within 6 h from onset. Eligible patients received IAT when immediately available and IVT otherwise. All patients were followed by ophthalmologists to assess best-corrected visual acuity (BCVA) and visual complications, and by neurologists for aetiological workup. Visual amelioration was defined as improvement of at least one Early Treatment Diabetic Retinopathy Study (ETDRS) letter from baseline to 1 week.

RESULTS

Of 49 patients with CRAO, 15 (30.6%) received reperfusion therapies (12 IVT, 3 IAT). Presentation beyond 6 h was the main contraindication. Patients receiving reperfusion therapies had better rates of visual improvement (33.3% vs 5.9%, p = 0.022). There were no complications related to reperfusion therapies. Rates of neovascular glaucoma were non-significantly lower in patients receiving reperfusion therapies (13.3% vs 20.6%, p = 0.701). Similar rates of atherosclerotic, cardioembolic and undetermined aetiologies were observed, leading to 10 new diagnosed atrial fibrillation and five carotid revascularizations.

CONCLUSION

A comprehensive acute management of CRAO is feasible despite low incidence. In our study, reperfusion therapies were safe and associated with higher rates of visual recovery. A similar etiological workup than ischemic stroke led to of high proportion of underlying aetiologies.

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.

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.

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.