Intra-Arterial Tissue Plasminogen Activator for Central Retinal Artery Occlusion

Abstract

Purpose: To investigate the benefit of early intra-arterial tissue plasminogen activator (IAT) for treatment of central retinal artery occlusion (CRAO).

Patients and methods: Fifteen eyes of 15 patients presenting with acute CRAO were included in this retrospective consecutive interventional case series. Patients were excluded if treatment with IAT was not initiated within 12 hours. The diagnosis was confirmed by an ophthalmologist. IAT was performed via a transfemoral arterial approach. Tissue plasminogen activator (tPA) was infused into the ophthalmic artery in aliquots up to 3mg to a maximum of 22mg. Paracentesis was done at the ophthalmologist's discretion. The primary outcome measure was visual acuity after three weeks. Adverse events were recorded during treatment and follow-up visits.

Results: After treatment with IAT, there was a statistically significant improvement in visual acuity, with a mean change of -0.76 (SD 0.91; range -2.4 to 0.85) logMAR (p=0.006). Vision improved by 3 or more lines in 53%, and of these, the mean Snellen visual acuity improvement was >6 lines. Notably, 4 patients (27%) improved from CF or worse to 20/80 or better. The mean dose of tPA used was 17mg and the mean time to treatment was 8.83 hours (range: 5.5 to 12 hours). There were no statistically significant differences based on time to treatment, dose of tPA, or use of a paracentesis. No major adverse events were recorded.

Conclusion: IAT was safe and showed significant visual improvement in this small uncontrolled study. Larger studies and efforts to decrease time to treatment should be initiated to optimize outcomes.

Keywords: CRAO; intervention; ophthalmic artery; tPA; treatment.

Figure 1

A histogram demonstrating the number of lines of improvement in Snellen acuity by the frequency of occurrence, for patients treated with intra-arterial tPA for CRAO. Of the eight (53%) eyes that improved by more than three (right of the dotted line), six (75%) improved by five lines or more. Only five (33%) eyes showed no improvement or worsening, while two (13%) improved although by less than three lines.

Figure 2

Box plots representing best-corrected visual acuity before and after intervention with intra-arterial tPA for CRAO. In A and B (left), results are from all eyes (n=15) that received intervention. In C and D (right), results are from the subset of eyes (n=8) with improvement of 3 or more lines of Snellen visual acuity improvement, demonstrating the magnitude of visual improvement in cases of successful treatment. Statistical testing was done using logMAR values. ***statistical significance, p<0.05.

Figure 3

Linear regression analysis of visual acuity at 3-weeks post intervention (y-axis) as a function of visual acuity at initial presentation (x-axis) of eyes treated with intra-arterial tPA for CRAO. Results demonstrate a moderate to high association (r=0.506) with borderline statistical significance (p=0.054).

Figure 4

Left internal carotid artery cranial diffusion subtraction angiography images before and after tPA thrombolysis for CRAO. Lateral view shows minimal but present retinal blush (black arrows) before tPA injection (A). After tPA injection, improvement of the retinal blush (black arrows) is observed (B).