Tenecteplase in the acute management of branch retinal vein occlusion.
The effect of Tenecteplase on intravenous thrombus and retinal blood flow in patients with branch retinal vein occlusion (BRVO).
Lions Eye Institute
40 participants
Jan 15, 2016
Interventional
Conditions
Summary
The primary aim of this study is to show that an injection of 100 micrograms of Tenecteplase (TNK) into the back of the eye will dissolve the clot and restore venous outflow within a week in patients who have recently suffered a branch retinal vein occlusion (BRVO) (clot in a branch of the retinal vein). Laser treatment has been the standard treatment for BRVO, and is now superseded by injecting anti-VEGF antibodies into the back of the eye. The visual outcome in patients treated this way has improved, but vision does not always return and ongoing injections are often required. Attempts at breaking the clot have been tried using tissue plasminogen activator (tPA), but they have not been effective. TNK is a third generation thrombolytic developed to address some of the short comings of tPA. Our research has shown that TNK is less toxic than tPA, it has a shorter clot contact time to be effective and it is able to penetrate the retina. We have used TNK to treat sub-retinal macula haemorrhage in humans without any problems. In this study, forty patients with a BRVO of less than 3 weeks will be enrolled with a 1:1 randomisation to the TNK treatment (100 micrograms) or sham treatment. Patients will be recruited from the retinal clinics at Royal Perth Hospital and the Lions Eye Institute. At the Baseline visit, consent will be obtained before any study procedure occurs. The study procedures are: best corrected visual acuity examination, ophthalmic examination (eye examination), photography (includes fluorescein angiography, colour photos and optical coherence tomography (OCT)), optical coherence tomography angiography (OCTA) and flowmetry. If eligible, the study participant will be randomised and treated at Day 0. The study procedures outlined above will be repeated at Day 2, Day 7,Day 30 and Day 90. All participants will start anti-VEGF treatment at Day 7; the current standard treatment. The Day 30 examination will determine if there is evidence of the clot reforming. We aim to show the resolution of the clot and improved retinal blood flow over the area of the blocked vein within a week of the TNK injection using the data from the fluorescein angiography, OCT and flowmetry. If the results are promising, then an application for NH&MRC funding for a multicentre study will be sought.
Eligibility
Inclusion Criteria10
- Foveal centre involved macular oedema secondary to BRVO less than 3 weeks in duration.
- Major supero-temperal or infero-temperal BRVO.
- Mean central foveal thickness greater or equal to 250 microns on spectral domain OCT.
- Adults greater or equal to 18 years.
- Best corrected visual acuity 20/40 to 20/320 (73-24 letters on ETDRS chart).
- Clear ocular media and adequate pupillary dilation.
- Intraocular pressure equal or less than 25mmHg.
- Written informed consent.
- No other significant ocular pathology.
- Willing, committed and able to return for all clinic visits and complete all study related procedures.
Exclusion Criteria18
- Any previous treatment for BRVO.
- Brisk afferent pupillary defect.
- Evidence on examination of any diabetic retinopathy.
- Women of child bearing potential not using contraception, as well as women who are breastfeeding.
- Known sensitivity to study drug or class of study drug.
- Use of any other investigational agent in the last 30 days.
- Any other ocular condition in the study eye that would prevent improvement in visual acuity, e.g.macular ischaemia, underlying macular degeneration, epi-retinal membrane.
- Neovascularisation of the iris, dics or retina.
- Previous treatment with intravitreal corticosteroids, intravitreal anti-VEGF agents or macular grid laser in the previous 3 months.
- Aphakia or presence of anterior chamber lens in the study eye.
- Significant media opacities such as cataract.
- Previous pars plana vitrectomy.
- History of retinal detachment or surgery for retinal detachment.
- Any condition which would preclude a patient's ability to comply with the study requirements or to be available for the duration of the study.
- Any active infection involving ocular adnexa including infectious conjunctivitis, keratitis, sclertitis, endophthalmitis as well as idiopathic or autoimmune-associated uveitis in either eye.
- Extra capsular extraction of cataract with phacoemulsification within 3 months preceding baseline, or a history of post-operative complications within 12 months preceding baseline in the study eye (uveitis, cyclitis etc.).
- Contra indication to pupil dilation in either eye.
- Allergy to fluorescein.
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Interventions
Patients with a branch retinal vein occlusion (BRVO) less than 3 weeks will receive one intraocular injection of 100 micrograms Tenecteplase or sham injection. The procedure will be performed by the study investigator and will follow the Royal Australian and New Zealand College guidelines for intraocular injection. For the sham injection procedure, an empty syringe hub will be placed against the eye. The randomisation will be 1:1. Forty patients will be recruited to the study. Optical Coherence Tomography (OCT) will be used to measure centre point foveal thickness in the macula and to estimate the volume of the intraluminal clot. Fluorescein angiography (FA) will measure retinal flow over the blockage. Retinal blood flowmetry will measure retinal blood flow in the area of the BRVO. Best corrected vision will be measured using an ETDRS Lighthouse 4 meter chart. Optical Coherence Tomography Angiography (OCTA) will be used to examine changes to the radial peripapillary capillaries and the deep capillary networks. At the Day 7 visit, anti-VEGF treatment will start.
Locations(2)
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ACTRN12615000185561