COMMENTARY

Tissue Plasminogen Activator for the Treatment of Central Retinal Artery Occlusion

Rod Foroozan, MD

Disclosures

January 06, 2009

Introduction

Central retinal artery occlusion (CRAO) is one of the most common causes of acute visual loss from retinovascular disease. There has been no proven therapy for CRAO. A number of treatments have focused on therapy directed to the eye (including lowering of intraocular pressure via paracentesis, ocular massage, and embolectomy via vitrectomy). Parallels have been drawn between CRAO and stroke, prompting the use of various treatments traditionally used for stroke for retinal arterial obstruction. One example is the use of tissue plasminogen activator (TPA), a treatment proven to be helpful in some patients with stroke.[1] The authors of this interventional case series evaluated the visual outcomes of 28 eyes treated with TPA for CRAO.

 

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

 

Hattenbach LO, Kuhli-Hattenbach C, Scharrer I, Baatz H
Am J Ophthalmol. 2008;146:700-706

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

Hattenbach LO, Kuhli-Hattenbach C, Scharrer I, Baatz H
Am J Ophthalmol. 2008;146:700-706

 

Summary

All patients had best corrected visual acuity of less than or equal to 20/100 at study enrollment and experienced symptoms for less than 12 hours before the onset of treatment. Visual acuity improved 3 or more lines in 9 eyes, was stable in 18 eyes, and worsened in 1 eye. Patients who were treated earlier (within 6.5 hours of symptom onset) were statistically more likely to have a good visual outcome compared to those treated later.

Comment

Treatment of CRAO with intravenous TPA has been previously attempted. Prior studies have used both intra-arterial and intravenous routes of delivery of TPA. Studies reviewing the cumulative experience of TPA and CRAO have not found definite proof of visual improvement. This study raised important questions about the time delay that is inherent between the onset of symptoms and the potential use of TPA. The authors noted that earlier treatment is of advantage to patients; 7 of 17 patients treated within 6.5 hours of symptom onset showed an improvement in visual acuity to 20/50 or better.

A potential problem with this therapy is the risk for systemic side effects such as intracranial hemorrhage. No hemorrhagic complications were noted in this study; however, the number of patients enrolled was small.

The accompanying editorial[2] asks several questions regarding the treatment of CRAO with TPA, including:

  • Is it time to consider treating CRAO with thrombolytics?

  • Would thrombolysis work in CRAO?

  • Are retrospective studies and case series of thrombolysis for CRAO sufficient to judge efficacy?

  • What has been learned from prior studies on CRAO and thrombolysis, and is a randomized trial needed?

It would be extremely difficult to complete a randomized trial with adequate power to determine whether thrombolysis is effective in treating CRAO. Studies such as this continue to raise more questions than they answer. As with many studies on CRAO, the measurement of visual field as a primary or secondary outcome was not mentioned.

Abstract

Comments

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