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

Acute monocular visual loss: time to call the stroke team?

A man in his 90s presented with acute monocular loss of vision; the emergency department triage alerted the stroke team. He underwent urgent parallel assessments by the stroke and ophthalmology teams and was diagnosed with central retinal artery occlusion. The ultimate decision was made to manage him conservatively, rather than with intravenous thrombolysis, and his visual function has remained poor. We discuss the current evidence for using intravenous thrombolysis in people with central retinal artery occlusion and use this case to exemplify the practical issues that must be overcome if ongoing randomised clinical trials of central retinal artery occlusion confirm a definite benefit from using intravenous thrombolysis.

Thrombolysis in acute retinal ischemia treated with tenecteplase

Central retinal artery occlusion (CRAO), a type of acute retinal arterial ischemia, analogous to an ocular stroke, is a medical emergency that warrants immediate diagnosis and treatment. CRAO usually presents with sudden, painless, monocular vision loss. Ipsilateral carotid artery disease is an important associated finding in these patients. The primary limitation to effective treatment of CRAO is that patients are rarely seen in the acute stage. Moreover, there are no guidelines for effective treatment. We report a patient with right CRAO whose treatment with intravenous thrombolysis with tenecteplase and anterior chamber paracentesis with ocular massage resulted in a good clinical outcome.

Exploring Superselective Intraarterial Thrombolysis for Autologous Fat Injection-Induced Vision Loss

BACKGROUND

Intravascular injection represents the most severe complication in fat transplantation procedures. Currently, the prognosis for patients who suffer from blindness due to fat transplantation-induced ocular vascular occlusion is far from optimistic.

OBJECTIVES

The aim of this study was to explore and evaluate the efficacy and safety of arterial thrombolysis in the treatment of ocular vascular occlusion caused by fat transplantation.

METHODS

We analyzed the data of 12 patients who underwent intraarterial thrombolysis and conservative treatments for facial autologous fat grafting-associated ocular vascular occlusion. Among the cases, there were 6 instances of ophthalmic artery embolism and 6 cases of central retinal artery occlusion. All patients suffered with sudden blindness, sometimes accompanied by eye pain, ptosis, strabismus, skin necrosis at the injection site, or cerebral microinfarction. They received symptomatic conservative treatments and intraarterial thrombolysis, encompassing mechanical vessel recanalization, vessel dilation, and dissolution of thrombus constituents.

RESULTS

Following intraarterial thrombolysis, a noteworthy improvement in the blood flow of both the main trunk and peripheral branches of the ophthalmic artery was observed in the majority of patients when contrasted with their pretreatment status. One patient experienced a headache intraoperatively, while no significant discomfort was reported by the remaining patients. After conservative treatments and intraarterial thrombolysis, all patients experienced improvement in ocular symptoms, skin necrosis, and cerebral infarction. Three patients demonstrated improvement in visual acuity. These patients had surpassed the recommended time window for treatment, yet the occlusion of the ophthalmic artery was not complete.

CONCLUSIONS

Intraarterial thrombolysis combined with conservative treatments achieves early perfusion and is expected to promote visual recovery. Hospitals that possess the necessary treatment capabilities are encouraged to establish this therapeutic pathway.

Evaluation of Increase in Retinal Thickness as Diagnostic Marker in Central Artery Occlusion

PURPOSE

To evaluate the increase in retinal thickness as a marker in predicting the onset of central retinal artery occlusions.

METHODS

Retrospective clinical study conducted at one Swiss hospital. Electronic records were filtered for patients with artery occlusions. Optical coherence tomography data, including time between the imaging and ischemic event, were reviewed. Increase in relative retinal thickness was measured, defined as an increase in retinal thickness compared to the unaffected partner eye. This was correlated with the time from symptom onset. A cutoff value of relative increase of < 24.5% was applied, as suggested in previous studies. The results were compared to the time gathered from the electronic records, and sensitivity, specificity, positive predictive value as well as negative predictive value were calculated for predicting an ischemia time of < 4.5 h.

RESULTS

Forty-two eyes from 41 patients with central artery occlusions were identified. Fourteen were female. Mean age was 66.4 ± 15.8 years. Initial corrected visual acuity was 2.41 ± 0.68 logMAR, and 2.13 ± 0.87 logMAR at the last follow-up (p > 0.05). Of eyes with a visual acuity of counting fingers (n = 38) or worse, 89.5% showed no improvement during follow-up, while eyes with logMAR 1 or better (n = 4) improved. Thirteen eyes (13 patients) presented within 4.5 h of the ischemic event. Four patients received i. v. thrombolysis, with visual recovery in one. In 12 eyes with an ischemia time of < 4.5 h, relative increase was below 24.5%. In the remaining 29 eyes with > 4.5 h, relative increase was below 24.5% in 4 eyes and above 24.5% in 25 eyes. This yielded a sensitivity of 92.3%, a specificity of 86.2%, with a positive predictive value of 75.0% and a negative predictive value of 96.2%.

CONCLUSION

Central retinal artery occlusion is associated with severe vision loss. There is no current established therapy. Parameters that objectify the presence of a therapeutic window for thrombolysis are gaining in importance as patient history is often imprecise. Relative retinal thickness increase proved a noninvasive imaging parameter demonstrating adequate performance in detecting patients within the therapeutic window of thrombolysis. Further investigation of this parameter in central retinal occlusion is warranted.

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.

Safety and effectiveness of IV Thrombolysis in retinal artery occlusion: A multicenter retrospective cohort study

BACKGROUND

Retinal artery occlusion (RAO) may lead to irreversible blindness. For acute RAO, intravenous thrombolysis (IVT) can be considered as treatment. However, due to the rarity of RAO, data about IVT safety and effectiveness is limited.

METHODS

From the multicenter database ThRombolysis for Ischemic Stroke Patients (TRISP), we retrospectively analyzed visual acuity (VA) at baseline and within 3 months in IVT and non-IVT treated RAO patients. Primary outcome was difference of VA between baseline and follow up (∆VA). Secondary outcomes were rates of visual recovery (defined as improvement of VA ⩾ 0.3 logMAR), and safety (symptomatic intracranial hemorrhage (sICH) according to ECASS II criteria, asymptomatic intracranial hemorrhage (ICH) and major extracranial bleeding). Statistical analysis was performed using parametric tests and a linear regression model adjusted for age, sex and baseline VA.

RESULTS

We screened 200 patients with acute RAO and included 47 IVT and 34 non-IVT patients with complete information about recovery of vision. Visual Acuity at follow up significantly improved compared to baseline in IVT patients (∆VA 0.5 ± 0.8, p < 0.001) and non-IVT patients (∆VA 0.40 ± 1.1, p < 0.05). No significant differences in ∆VA and visual recovery rate were found between groups at follow up. Two asymptomatic ICH (4%) and one (2%) major extracranial bleeding (intraocular bleeding) occurred in the IVT group, while no bleeding events were reported in the non-IVT group.

CONCLUSION

Our study provides real-life data from the largest cohort of IVT treated RAO patients published so far. While there is no evidence for superiority of IVT compared to conservative treatment, bleeding rates were low. A randomized controlled trial and standardized outcome assessments in RAO patients are justified to assess the net benefit of IVT in RAO.

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.

Intravenous Thrombolysis for Central Retinal Artery Occlusion: A Look at the Literature for the Emergency Medicine Physician

Central retinal artery occlusion (CRAO) is a subtype of ischemic stroke and true ocular emergency presenting with acute, painless, monocular vision loss. Typical findings include poor visual acuity (VA), impaired color vision, relative afferent pupillary defect, and on fundoscopic evaluation, retinal edema, cherry red spot, and occasionally visualization of retinal artery emboli. While there are no proven treatments for CRAO, options include orbital massage, hyperbaric oxygen therapy, and intra-arterial or intravenous thrombolysis (IVT). This study reviews the current literature on the efficacy of IVT for patients affected by acute, symptomatic CRAO and provides an up-to-date, evidence-based background for emergency physicians (EPs) who evaluate and manage these patients.

Neuroprotection for Nonarteritic Central Retinal Artery Occlusion: Lessons from Acute Ischemic Stroke

Nonarteritic central retinal artery occlusion (NA-CRAO) is a variant of acute ischemic stroke (AIS) and is a cause of sudden severe loss of vision. There are guidelines by the American Heart Association and the American Stroke Association for the care of CRAO patients. This review explores the basis of retinal neuroprotection for CRAO and its potential for improving the outcome of NA-CRAO. Recently, there have been significant advances in research into the use of neuroprotection to treat retinal diseases, including retinal detachment, age-related macular degeneration, and inherited retinal diseases. Also, neuroprotective research in AIS has been extensive, and newer drugs tested, including Uric acid, Nerinetide, and Otaplimastat, with promising results. Progress in cerebral neuroprotection after AIS offers hope for retinal neuroprotection after CRAO; and a possibility of extrapolating research findings from AIS into CRAO. Combining neuroprotection and thrombolysis can extend the therapeutic window for NA-CRAO treatment and potentially improve outcomes. Experimented neuroprotection for CRAO includes Angiopoietin (Comp Ang1), KUS 121, Gene therapy (XIAP), and hypothermia. Efforts in the field of neuroprotection for NA-CRAO should focus on better imaging to delineate the penumbra after an acute episode of NA-CRAO (using a combination of high-definition optical coherence angiography and electrophysiology). Also, research should explore details of pathophysiologic mechanisms involved in NA-CRAO, allowing for further neuroprotective intervention, and closing the gap between preclinical and clinical neuroprotection.

Thrombolysis in central retinal artery occlusion: a retrospective observational study

BACKGROUND

There is no evidence-based therapy for non-arteritic central retinal artery occlusion (NA-CRAO). Intravenous thrombolysis (IVT) with alteplase in a time window < 4.5 h may lead to a favorable outcome. Purpose of this study was to investigate the feasibility, efficacy and safety of IVT in patients classified as functionally blind.

METHODS

We conducted a retrospective observational study of NA-CRAO-patients. All patients underwent an ophthalmological and neurological examination including cerebral magnetic resonance imaging (MRI) for assessment of additional stroke lesions. Patients were treated either conservatively or with IVT within 4.5 h. Visual acuity (VA) was evaluated in logMAR and a categorical analysis was performed.

RESULTS

Thirty-seven patients were included in the study, 21 patients in the conservative treatment group (CTG) and 16 patients in the IVT group. The median logMAR visual acuity at admission and discharge was similar in both groups. The medium symptom to treatment time in the IVT group was 158.0 min. 3 patients (19%) of the IVT group showed a favorable outcome, all CTG patients remained at the level of functional blindness. No serious adverse events were observed after IVT. MRI showed additional acute stroke in over one-third of the patients (n = 14).

CONCLUSIONS

Early intravenous thrombolysis therapy according to the current stroke protocol n a time window up to 4.5 h after the onset of symptoms was feasible and might be a potential treatment option for NA-CRAO. Patients with NA-CRAO are at very high risk of ischemic stroke and MRI should be done in all patients for optimized treatment and secondary stroke prevention. A prospective randomized study is required.

Current diagnosis and treatment practice of central retinal artery occlusion: results from a survey among German stroke units

Background

Central retinal artery occlusion (CRAO) is a neuro-ophthalmological emergency whose optimal management is still under debate and due to the absence of definite guidelines, practice is expected to vary. We aimed to characterize early evaluation as well as acute treatment and diagnostic approaches in German hospitals with a stroke unit (SU).

Methods

In 07/2021, all 335 certified German SUs were invited to participate in an anonymous online survey endorsed by the German Stroke Society on emergency department care organization, diagnostic procedures, and treatment of patients with unilateral vision loss (UVL) subsequently diagnosed with CRAO.

Results

One hundred and sixty-three (48.6%) of the 335 eligible centers responded. Most (117/135; 86.7%) stated that UVL patients were treated as an emergency, in 62/138 (44.9%) hospitals according to specific guidelines. First-line evaluation was performed by neurologists in 85/136 (62.5%) hospitals, by ophthalmologists in 43/136 (31.6%) hospitals. Seventy of 135 (51.9%) respondents indicated a lack of on-site ophthalmological expertise. Seventy-four of 129 (57.4%) respondents performed thrombolysis in CRAO and 92/97 (94.8%) stated that patients with CRAO–if admitted to neurology–were treated on a SU.

Conclusions

Our findings reflect notable heterogeneity in early intrahospital care of CRAO in German SUs but demonstrate a preference for work-up and management as acute stroke by the involved neurologists. Streamlining interdisciplinary emergency evaluation is essential for ongoing and future prospective trials.

Supplementary Information

The online version contains supplementary material available at 10.1186/s42466-022-00193-w.

[Cardiovascular risk factors, haemostasis and antithrombotic treatment in retinal vessel occlusion]

Venous and arterial retinal vascular occlusions are age-related disorders, generally associated with classical cardiovascular risk factors, rather than an isolated ocular disease. As affected patients often also have an increased general risk for other vascular diseases, such as ischemic stroke, an interdisciplinary clarification of cardiovascular risk factors and systemic comorbidities is essential for all patients. Extended hemostaseological investigations may be recommended in those patients who do not match the typical risk profile. Patients at a young age by the time of manifestation, without conventional risk factors as well as patients with an increased risk of developing antiphospholipid syndrome may require a selective clinical investigation including testing for thrombophilic risk factors. Recent studies have clearly demonstrated an association between coagulation and lipid metabolism disorders and the development of both retinal vein and artery occlusions in specific subgroups of patients. Therapeutic approaches to treat retinal vascular occlusions or reduce the long-term risk of recurrences with anticoagulant or antiplatelet drugs have not gained widespread acceptance. However, intravenous thrombolysis may be a valuable treatment option for central retinal artery occlusions within a short time to treatment therapeutic window. For defined disorders of the coagulation system, the administration of antithrombotic drugs to reduce the general vascular risk can be a reasonable approach. This article provides an overview of cardiovascular risk factors, the general vascular risk and the current state of knowledge on ophthalmologically relevant disorders of coagulation and lipid metabolism in patients with venous and arterial retinal vascular occlusions.

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.

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.

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.

CASE SERIES OF HYPERBARIC OXYGEN THERAPY FOR CENTRAL RETINAL ARTERY OCCLUSION

PURPOSE

To retrospectively report the outcomes of patients presenting to our facility with central retinal artery occlusion and receiving therapy with hyperbaric oxygen (HBO).

METHODS

This was a retrospective, chart review at a single hospital center. Patients with diagnosed central retinal artery occlusion were treated with HBO twice daily for 5 days during their inpatient stay for a total of 10 HBO treatments. Main outcome was change from the documented presenting best-corrected visual acuity to discharge best-corrected visual acuity. Thirty-nine patients with central retinal artery occlusion were included in the analysis during a 30-month period.

RESULTS

Twenty-eight of 39 patients (72%) had some improvement in acuity. There was a mean of 5.05 lines of improvement using a modified Snellen chart after completing their HBO treatment course. Patients treated within 12 hours of symptom onset showed the greatest improvement in their visual acuity (6.11 mean lines of improvement). Complications of therapy included middle ear barotrauma (10/39) and confinement anxiety (1/39) and did not interfere with the therapy regimen or hospital course.

CONCLUSION

This retrospective case series supports the use of emergent HBO therapy as a viable treatment option for patients with central retinal artery occlusion. Hyperbaric oxygen therapy was safely administered and well tolerated.

Intravenous thrombolysis in patients with central retinal artery occlusion: a systematic review and meta-analysis

BACKGROUND AND PURPOSE

To investigate the efficacy and safety of intravenous thrombolysis (IVT) with alteplase in patients with central retinal artery occlusion (CRAO).

METHODS

We searched the database of PubMed and EMBASE for potentially eligible studies that reported IVT in CRAO patients from their dates of inception to May 19, 2021. The rate and odds ratios (OR) of best-corrected visual acuity (BCVA) improvement, mean difference (MD) of BCVA with 95% confidence interval (CI) were pooled with random effects model.

RESULTS

We included 8 studies enrolling 316 CRAO patients, among them, 157 patients received IVT with alteplase while 159 patients did not. The rate of best BCVA improvement was 47% (95% CI 33-62%) in the CRAO patients treated with IVT, which was higher than that of 12% (95% CI 1-23%) in those without IVT (OR 5.97, 95% CI [2.77-12.86]). In the setting of similar baseline BCVA (MD [logMAR] 0.16, 95% CI [- 0.15 to 0.46]), compared with those who did not receive IVT, the CRAO patients who received IVT had better best BCVA (MD [logMAR] - 0.23, 95% CI [- 0.44 to - 0.02]), but had no significant better final BCVA (MD [logMAR] - 0.10, 95% CI [- 0.32 to 0.12]). Two CRAO patients had complicated symptomatic intracranial hemorrhage after IVT.

CONCLUSIONS

IVT treatment might be effective and safe for CRAO patients, but ocular-specific complications which were not associated with thrombolysis could affect final visual acuity.

[Acute diagnostics of central retinal artery occlusion and biomarkers of ischemia : Diagnostics with consequences?]

BACKGROUND

Acute central retinal artery occlusion (CRAO) represents an ophthalmological emergency with neurological implications, which must be immediately investigated and treated. Intravenous thrombolysis could improve the prognosis only within the first 4.5 h due to limited retinal tolerance to ischemia. Accordingly, ophthalmological acute diagnostics should be reduced to the minimum necessary followed by immediate referral to a clinic with neurovascular expertise. The typical anamnesis is well-suited for triaging and should be carried out ín a standardized way in order to determine the onset of symptoms as exactly as possible. In addition to pathognomic findings in fundoscopy, there are characteristic ischemia-related changes in optical coherence tomography (OCT), which document ischemia in the inner retina and under some circumstances can provide inferences for the onset of ischemia.

OBJECTIVE

This review article summarizes the acute ophthalmological diagnostic management of acute CRAO with a focus on the typical OCT and transorbital ultrasound (TOUS) findings and discusses their potential use as ischemic biomarkers.

CONCLUSION

Characteristic biomarkers make OCT an important diagnostic tool in the management of acute CRAO. Additional information can be obtained by TOUS. With an evidence-based treatment established in the future both tools could be used for indications for treatment and for estimating the prognosis.

[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.

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.

Intravenous Recombinant Tissue-Type Plasminogen Activator Thrombolysis for Acute Central Retinal Artery Occlusion

INTRODUCTION

Central retinal artery occlusion (CRAO), an ocular stroke, causes severe and permanent visual impairment. Thrombolytic therapy is currently the main treatment option for CRAO. Intravenous thrombolysis with recombinant tissue-type plasminogen activator (rt-PA) has been extensively applied in the treatment of CRAO with the proven advantages of effectiveness and safety. This meta-analysis aimed to assess the efficacy of intravenous rt-PA thrombolysis for the management of CRAO by evaluating the pooled evidence.

METHODS

A comprehensive literature search of electronic databases including PubMed, OVID, and Cochrane Library was conducted up to and including March 2019. All studies reporting visual outcomes after CRAO with thrombolytic therapy were collected. Data on visual acuity and adverse events were recorded and assessed in this analysis. Data were inputted into the statistical software of STATA. The studies were weighed by the inverse of the variance and merged in a random-effects model.

RESULTS

The systematic review process yielded 7 eligible studies including 121 patients with CRAO who received the intravenous rt-PA treatment. Sixty-two patients showed improvement in visual acuity (52.0%; 95% CI, 34.0%-70.0%) following rt-PA intravenous thrombolytic therapy. The observed improvement rate in the intravenous rt-PA treatment group was significantly higher than the conservative treatment group (40.4% vs. 13.0%; OR = 5.16; 95% CI, 1.90-14.05). The incidence rate of complications was relatively low (11 out of the 121 patients). Hemorrhage (9/11) was the major reported complication. Mortality was zero.

DISCUSSION

This meta-analysis indicated that intravenous rt-PA thrombolysis could be an effective and safe strategy for the management of CRAO. However, a more detailed large-scale clinical trial is warranted to strengthen the evidence-based therapeutic guidance.

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.

Determination of Ischemia Onset Based on Automatically Generated Spectralis SD-OCT Values in Acute Central Retinal Artery Occlusion

Acute central retinal artery occlusion (CRAO) induces a time-dependent increase in retinal thickness. By manually measuring the relative retinal thickness increase (RRTI) in comparison to the contralateral eye based on optical coherence tomography (OCT), ischemia onset within the past 4.5 hours could be determined with 100% sensitivity and 94.3% specificity. To enable examiner-independent and quicker diagnostics, we analyzed the RRTI using the automatic retinal thickness measurement. In this retrospective study, 28 eyes were evaluated with an acute CRAO (<46 hours). All patients received a Spectralis SD-OCT image of both eyes. The RRTI was calculated for the ETDRS sectors using the Segmentation Module for Single Retinal Layer Analysis. Receiver operating characteristic (ROC) analysis was performed to determine patients ≤4.5 hours by RRTI. In all sectors, time to OCT (TTO) and RRTI correlated positively. The optimal cutoff point to detect CRAOs ≤4.5 hours was between 18.7% nasally and 22.9% RRTI temporally. Sensitivity and specificity varied between the sectors with 90-95% sensitivity and 89-100% specificity. In conclusion, the automatic measurement of RRTI also allows the differentiation of CRAOs within a possible therapeutic time window ≤4.5 hours and CRAOs ≥4.5 hours with a high sensitivity and specificity. Additionally, it offers quicker, easier, and a user-independent assessment of ischemia onset, helping to set a base for establishing automatic indices generated by the OCT machines.

Optical coherence tomography-based determination of ischaemia onset - the temporal dynamics of retinal thickness increase in acute central retinal artery occlusion

PURPOSE

Acute central retinal artery occlusion (CRAO) induces ischaemic retinal oedema. The purpose of this study was to define sensitivity and specificity of optical coherence tomography (OCT) based retinal thickness analysis in determining ischaemia onset in CRAO.

METHODS

The relative retinal thickness increase (RRTI) in comparison with the fellow eye was analysed retrospectively in OCT scans of 66 patients diagnosed with CRAO between January 2010 and December 2019 within 48 hr of ischaemia onset. The natural course of RRTI and the sensitivity and specificity of OCT-based determination of ischaemia onset in identifying CRAO within 4.5 hr using the RRTI were evaluated.

RESULTS

Relative retinal thickness increase (RRTI) in acute CRAO follows a hyperbolic curve with a steep incline within the early phase after which it reaches a plateau. Optical coherence tomography (OCT)-based retinal thickness analysis in CRAO allows to differentiate patients with ischaemia onset within the past 4.5 hr or thereafter with a sensitivity of 100% and a specificity of 94.3%.

CONCLUSION

Relative retinal thickness increase (RRTI) allows to identify CRAO patients that are eligible for a potentially beneficial reperfusion therapy within a therapeutic window of 4.5 hr with a high accuracy. Especially in patients with unknown ischaemia onset, this diagnostic tool could be of major importance in the future clinical management.

Retinal vascular occlusions

Acute retinal vascular occlusions are common causes of visual impairment. Although both retinal artery occlusions and retinal vein occlusions are associated with increased age and cardiovascular risk factors, their pathophysiology, systemic implications, and management differ substantially. Acute management of retinal artery occlusions involves a multidisciplinary approach including neurologists with stroke expertise, whereas treatment of retinal vein occlusions is provided by ophthalmologists. Optimisation of systemic risk factors by patients' primary care providers is an important component of the management of these two disorders.

Ophthalmology in Critical Care

Ophthalmic disease encountered in the intensive care unit (ICU) has a wide spectrum of prevalence and severity. Prolonged exposure of the cornea is common and preventable. Trauma, glaucoma, infection, vascular disease, and burns are among the potential causes of vision loss. Patients are predisposed to ocular complications by the ICU environment and critical illness itself. Critically ill patients require prioritization of life-sustaining interventions, and less emphasis is placed on ophthalmic disease, leading to missed opportunities for vision-saving intervention. It is therefore imperative for intensivists, nurses, and other providers to have an increased awareness and understanding of the broad range of ocular conditions potentially seen in the ICU.

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.

Intravenous Fibrinolysis for Central Retinal Artery Occlusion: A Cohort Study and Updated Patient-Level Meta-Analysis

BACKGROUND AND PURPOSE

Central retinal artery occlusion results in sudden, painless, usually permanent loss of vision in the affected eye. There is no proven, effective treatment to salvage visual acuity and a clear, unmet need for an effective therapy. In this work, we evaluated the efficacy of intravenous tissue-type plasminogen activator (IV alteplase) in a prospective cohort study and an updated systematic review and meta-analysis.

METHODS

We enrolled consecutive patients with acute central retinal artery occlusion within 48 hours of symptoms onset and with a visual acuity of <20/200 from January 2009 until May 2019. The primary outcomes were safety and functional visual acuity recovery. We compared rates of visual recovery between those treated with alteplase within 4.5 hours of symptom onset to those who did not receive alteplase (including an analysis restricted to untreated patients presenting within the window for treatment). We incorporated these results into an updated systematic review and patient-level meta-analysis.

RESULTS

We enrolled 112 patients, of whom 25 (22.3% of the cohort) were treated with IV alteplase. One patient had an asymptomatic intracerebral hemorrhage after IV alteplase treatment. Forty-four percent of alteplase-treated patients had recovery of visual acuity when treated within 4.5 hours versus 13.1% of those not treated with alteplase (P=0.003) and 11.6% of those presenting within 4 hours who did not receive alteplase (P=0.03). Our updated patient-level meta-analysis of 238 patients included 67 patients treated with alteplase within 4.5 hours since time last known well with a recovery rate of 37.3%. This favorably compares with a 17.7% recovery rate in those without treatment. In linear regression, earlier treatment correlated with a higher rate of visual recovery (P=0.01).

CONCLUSIONS

This study showed that the administration of intravenous alteplase within 4.5 hours of symptom onset is associated with a higher likelihood of a favorable visual outcome for acute central retinal artery occlusion. Our results strongly support proceeding to a randomized, placebo-controlled clinical trial.

Development of visual acuity under hyperbaric oxygen treatment (HBO) in non arteritic retinal branch artery occlusion

PURPOSE

Nonperfusion of retinal tissue due to arterial occlusion leads inevitably to mostly irreversible retinal damage. Until today no evidence-based treatment exists. Inhalation of 100% oxygen at high atmospheric pressure causes an increased solubility of oxygen in the blood that helps the retinal tissue to survive through diffusion in case of an artery occlusion till vascular recanalization occurs. Hence the purpose of this study is to compare the visual outcome in patients with retinal branch artery obstruction treated with hyperbaric oxygen versus patients treated with hemodilution only.

METHODS

Non-randomized, monocentric, retrospective study. Patients with diagnosis of non-arteritic retinal branch artery occlusion (BRAO) treated with hyperbaric oxygen therapy between 1997 and 2017. Exclusion criteria were central retinal artery occlusion, presence of a cilioretinal artery and arteritic cases. The control group was matched based on visual acuity (VA) at admission, age, and delay between symptoms and beginning of clinical care.

RESULTS

The control group and the matching oxygen group contained 14 patients each. Initial VA in the matched HBO group was 0.18 ± 0.19 and 0.23 ± 0.19 in the control group (p = 0.57). Final VA at discharge was 0.69 ± 0.29 in the matched oxygen group and 0.32 ± 0.23 in the control group (p = 0.0009). HBO-treated patients had a significant visual increase compared with the control group. The most common comorbidities were arterial hypertension and vascular sclerosis.

CONCLUSION

HBO treatment appears to have a beneficial effect on visual outcome in patients with retinal branch artery occlusion. HBO treatment could be a rescue therapy at an early stage of BRAO, especially to bridge the time of a potential reperfusion. However, further, prospective, randomized clinical trials are required to verify this assumption.

[Reduced Caliber of the Ophthalmic Artery in Magnetic Resonance Angiography in Patients after Retinal Artery Occlusion]

BACKGROUND

Retinal artery occlusion (RAO) is caused by embolic occlusion of retinal arteries. Previous strokes in the medical history were reported in up to 20% of patients. According to data from a computational blood flow analysis based on magnetic resonance imaging of a patient with RAO, about 90% of ascending emboli are washed into the brain, leaving speculations about further embolic sources for RAO, such as plaques or stenosis of the ophthalmic artery. The aim of this study was to examine the reduced caliber of the ophthalmic artery in magnetic resonance angiography (MRA).

PATIENTS AND METHODS

An analysis of a prospective case series of 9 patients with newly diagnosed RAO, presenting at the outpatient department. Magnetic resonance angiography of the brain, including the ophthalmic artery and carotid siphon was performed in all patients and evaluated by an experienced radiologist also specialised in neuroradiology. Outcomes were compared to an age-matched control group of 9 patients without RAO.

RESULTS

Four of 9 patients (44.4%) had a reduced caliber of the ophthalmic artery, two only at the side of RAO and another two bilateral. One of these cases also had a severe steno-occlusive disease of the internal carotid artery in the MRA, being in accordance with the results from duplex-sonography of the internal carotid artery. None of the patients in the control group had any signs of stenosis of the ophthalmic artery.

CONCLUSIONS

Reduced caliber of the ophthalmic artery in MRA is present in almost half of patients with RAO and indicates that steno-occlusive disease of the ophthalmic artery could be a possible source of emboli, causing RAO.

Neuro-Ophthalmology at the Bedside: A Clinical Guide

Neuro-ophthalmological signs and symptoms are common in the emergency department but are a frequent source of diagnostic uncertainties. However, neuro-ophthalmological signs often allow a precise neuro-topographical localization of the clinical problem. A practical concept is presented how to perform a neuro-ophthalmological examination at the bedside and to interpret key findings under the aspect of emergency medicine with limited resources.

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.

Hypothermia protects retinal ganglion cells against hypoxia-induced cell death in a retina organ culture model

BACKGROUND

Hypoxia contributes to retinal damage in several retinal diseases, including central retinal artery occlusion, with detrimental consequences like painless, monocular loss of vision. Currently, the treatment options are severely limited due to the short therapy window, as the neuronal cells, especially the retinal ganglion cells (RGCs), are irreversibly damaged within the first few hours. Hypothermia might be a possible treatment option or at least might increase the therapy window.

METHODS

To investigate the neuroprotective effect of hypothermia after retinal hypoxia, an easy-to-use ex vivo retinal hypoxia organ culture model developed in our laboratory was used that reliably induced retinal damage on a structural, molecular and functional level. The neuroprotective effect of hypothermia after retinal hypoxia was analysed using optical coherence tomography scans, histological stainings, quantitative real-time polymerase chain reaction, western blotting and microelectrode array recordings.

RESULTS

Two different hypothermic temperatures (30°C and 20°C) were evaluated, both exhibited strong neuroprotective effects. Most importantly, hypothermia increased RGC survival after retinal hypoxia. Furthermore, hypothermia counteracted the hypoxia-induced RGC death, reduced macroglia activation, attenuated retinal thinning and protected from loss of spontaneous RGC activity.

CONCLUSIONS

These results indicate that already a mild reduction in temperature protects the RGCs against damage and could function as a promising therapeutic option for hypoxic diseases.

Eye Opener in Stroke

Supplemental Digital Content is available in the text.

Retinal ischemia is a major cause of visual impairment in stroke patients, but our incomplete understanding of its pathology may contribute to a lack of effective treatment. Here, we investigated the role of mitochondrial dysfunction in retinal ischemia and probed the potential of mesenchymal stem cells (MSCs) in mitochondrial repair under such pathological condition.

Central retinal artery occlusion-A new, provisional treatment approach

The retinal ganglion cells infarcted in central retinal artery occlusion (CRAO) are the somata of the optic nerve axons, part of the central nervous system. Consequently, CRAO with inner retinal infarction is a small vessel stroke, usually with the devastating consequence of severe visual loss in the affected eye. At present, there is no generally accepted, evidence-based therapy of nonarteritic CRAO in contrast to ischemic cerebral stroke that has well-accepted treatment protocols. Widely divergent and controversial therapeutic options for CRAO reflect the desperation of treating physicians and disparate conflicting studies. We examine reasons why treatment of nonarteritic CRAO remains problematic and then suggest a provisional new approach to treatment based on updated understanding of CRAO pathophysiology and analysis of current therapeutic options and their rationales.

Optical Coherence Tomography Measurement and Visual Outcome in Acute Central Retinal Artery Occlusion

Purpose

This study investigated visual acuity (VA) values and differences depending on optical coherence tomography (OCT) findings in patients with acute central retinal artery occlusion (CRAO).

Methods

A retrospective chart review was performed on patients with acute CRAO who underwent macular and disc OCT. We evaluated changes in macular thickness and retinal nerve fiber layer (RNFL) thickness after acute CRAO onset based on OCT. We also determined the association of thickness changes with VA improvement.

Results

This study involved both eyes in a total of 12 patients with acute CRAO. A significant increase was observed in foveal (1 mm) thickness (p = 0.002), parafoveal (3 mm) thickness (p = 0.002), and peripapillary RNFL thickness (p = 0.005) in affected eyes with CRAO, but not in central foveal thickness (p = 0.266). A significant small difference in both eyes (affected eye – fellow eye) was shown in foveal (1 mm) and mean parafoveal (3 mm) thickness in the improved VA group (p = 0.008 and p = 0.004, respectively), but not in central foveal or peripapillary RNFL thickness (both p = 0.283).

Conclusions

Both macular and RNFL thickness increased in patients with acute CRAO. RNFL thickness decreased over time with progression of RNFL atrophy. Less macular damage caused by acute CRAO could be predicted by a small difference in macular thickness between eyes (affected eye – fellow eye). In such cases, patients had a greater chance of VA improvement.

Is Management of Central Retinal Artery Occlusion the Next Frontier in Cerebrovascular Diseases?

Central retinal artery occlusion (CRAO) is a medical emergency that, if not treated, may result in irreversible loss of vision. It continues to be an important cause for acute painless loss of vision. Amaurosis fugax or "transient CRAO" has long been considered an equivalent of transient cerebral ischemic event. Animal models, in addition to data from retrospective and randomized clinical studies, provide valuable insights into the time interval for irreversible retinal ischemia. Subset analyses from 2 large studies of patients with CRAO show benefit from treatment with thrombolysis within 6 hours from symptoms onset. Significant workflow improvements after the intra-arterial therapy trials for acute ischemic stroke have occurred world over in last 5 years. Patients with CRAO are uniquely suited to receive maximum benefits from the changes in workflow for treatment of patient's acute ischemic stroke. Just as in clinical triage of acute ischemic stroke, correct and timely diagnosis of patients with CRAO may help in preventing visual loss. The approach to acute ocular ischemia should mimic that used for acute brain ischemia. Comprehensive stroke centers would be ideal triage centers for these patients in view of availability of multidisciplinary participation from vascular neurology, neuroendovascular surgery, and ophthalmology. Time is Retina!

Treatment of Nonarteritic Acute Central Retinal Artery Occlusion

Central retinal artery occlusion (CRAO) is an event most often caused by an embolus originating in the ipsilateral carotid artery, aortic arch, or heart. CRAO may result from partial or complete occlusion of the central retinal artery (CRA), which acts as the primary blood supply to the inner neurosensory retina, and typically results in profound vision loss and permanent visual disability. No consensus has emerged regarding the optimal treatment of CRAO. All proposed treatments are of questionable efficacy and many have uncertain risk profiles. In certain circumstances, thrombolysis may be attempted as a treatment option; however, the evidence to support broad use of thrombolytics in the treatment of acute CRAO remains elusive. It is known that the risk factors that predispose to other cardiovascular and cerebrovascular events are often present in CRAO. Accordingly, identification of patients at highest risk of stroke and secondary prevention of ischemic events remains the primary focus of management. This review offers a summary of the clinical presentation, diagnosis, and prognosis of CRAO, with an emphasis on treatment options.

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.

Central retinal artery occlusion - rethinking retinal survival time

Background

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

Methods

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

Results

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

Conclusions

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

Use of recombinant tissue plasminogen activator for treatment of recalcitrant anterior uveitis: A case series

Management of inflammation after surgery for recalcitrant anterior uveitis is challenging. Herein, we report successful treatment using intracameral injection of recombinant tissue plasminogen activator (rtPA) in two patients with recalcitrant anterior uveitis, due to infective uveitis and Vogt-Koyanagi-Harada disease, respectively. A 40-year-old woman presented with bilateral redness and vision reduction that had persisted 2 weeks. She also had bilateral anterior uveitis, vasculitis, retinitis, and optic disc swelling. Serology was positive for Bartonella henselae and Toxoplasma gondii. She was treated using long-term systemic corticosteroids and appropriate antibiotics. Our second case; a healthy 30-year-old man with bilateral eye redness and reduced vision without pain, and associated with headache and tinnitus for 1 weeks. He showed bilateral granulomatous inflammation with vitritis, choroiditis, retinitis, and hyperemic optic disc. The patient was diagnosed with Vogt-Koyanagi-Harada disease and treated with systemic corticosteroids. Both patients developed secondary cataracts and glaucoma that necessitated surgical intervention. Persistent chronic inflammation led to the formation of a thick fibrin membrane anterior to the intraocular lens (IOL) after phacoemulsification surgery with IOL implantation. This membrane was removed surgically, and intracameral injection of rtPA (25 μg) was carried out. The persistent inflammation had resolved and visual acuity had significantly improved within 1 week of intracameral rtPA injection. There were no reported ocular or systemic side effects. Intracameral rtPA is beneficial in patients with recalcitrant anterior uveitis who have undergone intraocular surgery. In most cases, surgical intervention improves the patients' vision. Intracameral rtPA should be considered in cases of persistent inflammation of varying etiology.