[Intracerebral hemorrhage after systemic thrombolysis in patients with occlusion of the central retinal artery. Report of 2 cases]

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.

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.

Hyperbaric oxygen in the treatment of acute retinal artery occlusion

INTRODUCTION

Acute retinal artery occlusion (ARAO) is a major cause of sudden, painless visual loss, often leaving no useful vision in the affected eye. Its incidence is cited at 0.85 per 100,000 persons per year but may be higher because of under-reporting. The natural history is difficult to study, but a spontaneous resolution rate of < 1-8% for acute, non-arteritic ARAO has been cited. Occurrence in an only eye is devastating for the patient. There is currently no consensus regarding management of ARAO and little evidence to support any treatment modality. Despite only limited case series, hyperbaric oxygen treatment (HBOT) is recommended for ARAO by the Undersea and Hyperbaric Medical Society (UHMS) and by the European Committee for Hyperbaric Medicine.

METHODS

Between early 2003 and December 2012, all ARAO patients presenting to Christchurch Hospital were referred for consideration of HBOT. These 31 consecutive patients' medical records were reviewed retrospectively. The time delay from onset of visual loss to commencing HBOT; the presenting visual acuity; various demographic data; the HBOT administered and the outcome visual acuity were documented.

RESULTS

All 31 patients underwent at least one HBOT (median 4, range 1-7) at a pressure of 203-284 kPa for 1.5 to 2.0 h. One patient's treatment was terminated after 60 min at their request; another declined further HBOT and one suffered middle ear barotrauma. Thirteen patients also received anticoagulants at the discretion of the referring ophthalmologist. Twenty three patients had temporarily improved vision with the first HBOT. Seven patients had permanent, good visual recovery (6/18 or better; Snellen chart); and two only modest improvement (6/60). All nine patients who improved permanently were treated within 10 hours of symptom onset.

CONCLUSIONS

Where available, HBOT is indicated for ARAO. Our protocol may not have been aggressive enough and the UHMS protocol is recommended. A multi-centre, randomised controlled trial is feasible, but would be logistically difficult and expensive and may be ethically unsupportable given the lack of alternative, effective treatments.

Successful treatment of central retinal artery thromboembolism with ocular massage and intravenous acetazolamide

A 67-year-old woman presented with left-sided headache and blurred vision, worse during hypertensive episodes. CT angiography showed a 4 mm left internal carotid artery (ICA) aneurysm incorporating the ophthalmic artery. She passed a test balloon occlusion, so the aneurysm was coil occluded, without immediate complication. Four days postprocedure she experienced sudden loss of vision in the left eye and funduscopy showed central retinal artery occlusion secondary to emboli from the coiled aneurysm. She was treated promptly with intravenous acetazolamide and ocular massage and regained full visual acuity. Thromboembolism to the eye during or after neurointerventional treatment is a relatively rare but devastating complication. This report demonstrates the effectiveness of combined intravenous acetazolamide and ocular massage in dealing with this complication when delivered promptly.

Spontaneous and non-spontaneous bleeding complications in patients with oral vitamin K antagonist therapy

PURPOSE

The aim of the study was to evaluate potential differences between patients with spontaneous and non-spontaneous bleeding episodes during treatment with vitamin K antagonists which mainly resulted in compartment syndromes.

METHODS

The population in this study comprised 116 patients who suffered at least one bleeding complication which required surgical treatment during therapy with an oral vitamin K antagonist. The patients were treated between September 2001 and July 2008.

RESULTS

Significant differences were observed between the two patient groups with regard to the presence of renal failure, arterial hypertension, and diabetes mellitus, which occurred more frequently in patients with spontaneous bleeding. Also, significantly more patients with spontaneous bleedings developed compartment syndrome that needed emergency operation. Overall mortality was 9.6 %, was associated with multiorgan failure in all patients, and was not different between the two patient groups.

CONCLUSIONS

The identification of high-risk patients before treatment with an oral vitamin K antagonist is of major importance. The existence of over-anticoagulation syndrome and compartment syndrome is associated with significant mortality and morbidity and should not be underestimated.

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

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

SUMMARY

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

Thrombolysis for Central Retinal Artery Occlusion

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

A rare complication of embolization in juvenile nasopharyngeal angiofibroma

Juvenile nasopharyngeal angiofibroma (JNA) is one of the most common benign nasal cavity tumors of adolescence. It exhibits a strong tendency to bleed and despite being microscopically benign, its behavior is locally aggressive. Preoperative embolization is helpful to minimize intraoperative bleeding. However, embolization procedure may have some important thromboembolic complications such as central retinal artery occlusion. In this article, a young male with juvenile nasopharyngeal angiofibroma, who lost his vision in the left eye following embolization was presented and the possible therapeutic options in such a complication were discussed.

Selective intraarterial fibrinolysis of acute central retinal artery occlusion

PURPOSE

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

MATERIAL AND METHODS

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

RESULTS

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

CONCLUSION

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

[Occlusion of the retinal artery]

The occlusion of the retinal artery usually leads to sudden and, in most cases, continual visual impairment of the affected eye. This is an uncommon illness with a variable progression. To date it has not been possible to develop a generally recommended therapy using prospective, randomised studies, as is the case for circulatory impairment in other organs. Due to this uncertainty, the treatment of a retinal arterial occlusion is regarded as an ophthalmological emergency and a challenge for the attending practitioner. In this overview, the actual state of our knowledge on the pathogenesis of occlusion of a retinal artery as well as current and new therapies are presented.

Optic disk and retinal nerve fiber layer damage after transient central retinal artery occlusion: an experimental study in rhesus monkeys

PURPOSE

To evaluate the retinal tolerance time to acute ischemic insult in middle-aged or elderly rhesus monkeys with pre-existing atherosclerosis and arterial hypertension.

METHODS

In 39 eyes of 39 middle-aged and elderly rhesus monkeys with a mean age of 19.5 +/- 2. 8 years, occlusion of the central retinal artery was produced by temporary clamping of the central retinal artery at its site of entry into the dural sheath of the optic nerve for 97 to 300 minutes. Stereoscopic color fundus photography and fluorescein fundus angiography were performed before central retinal artery occlusion and serially thereafter. Retinal nerve fiber layer damage and optic disk changes were assessed by comparing morphometric evaluation of the color fundus photographs taken before central retinal artery occlusion and color fundus photographs taken at the end of the study.

RESULTS

There was a significant correlation between duration of central retinal artery occlusion and decreased visibility of retinal nerve fiber layer (P =.018) and increasing optic disk pallor (P =. 014), and a trend between residual retinal circulation and decreased visibility of retinal nerve fiber layer (P =.085) and optic disk pallor (P =.162). However, there was a marked interindividual variation between the length of central retinal artery occlusion and degree of increased optic disk pallor and decreased visibility of the retinal nerve fiber layer, even among eyes with similar duration of central retinal artery occlusion. Complete or almost total optic nerve atrophy and nerve fiber damage were present in all eyes in which the duration of central retinal artery occlusion was 240 minutes or more.

CONCLUSIONS

The findings of this study, compared with our previous study in young healthy rhesus monkeys, indicate that in middle-aged or elderly atherosclerotic and arterial hypertensive rhesus monkeys, central retinal artery occlusion for less than 100 minutes produced no apparent morphometric evidence of optic nerve damage; however, central retinal artery occlusion of 105 minutes but less than 240 minutes produced a variable degree of damage; central retinal artery occlusion for 240 minutes or more produced total or almost total optic nerve atrophy and nerve fiber damage.