Richard Jackson, MD
Mac Grory et al. have published data that all stroke neurologists on call have been waiting for. In hospital systems where there are ophthalmologists taking calls, usually the neurologist on call for stroke gets the stroke code page for acute onset loss of vision or the patient is referred to the ER for a diagnosis of CRAO for evaluation. There is an ensuing debate between the on-call neurologist and ER physician about what to do for this patient. As neurologists, we are taught that the eye is an extension of the brain, and infarcts to the eye are technically infarcts to the brain. However, there is no data on whether or not thrombolysis with alteplase is efficacious. The ophthalmologists cite a lack of efficacy in trials and only one randomized trial with a small sample of 25 that showed no benefit when treated with standard dose 0.9mg/kg IV-tPA but within 24 hours of onset. An even more difficult situation arises in the primary stroke centers that do not have ophthalmologists on call where the neurologist on call for stroke has to make a decision based on clinical judgement. Both of these scenarios usually end in poor visual acuity for the patient after medical treatment with monotherapy or dual therapy antiplatelet with or without permissive hypertension and statin treatment.
This study prospectively enrolled 112 patients within 48 hours of onset of symptoms from 2009 to 2019 and offered IV-tPA treatment to any presenting within 6 hours of onset until 2015 then afterwards within 4.5 hours. 22.3% of patients were treated with IV-tPA, 14.3% in the <4.5 hour window. 43.8% of patients treated with alteplase had recovery of visual acuity versus 13.1% of patients treated with high flow oxygen, aspirin and/or clopidogrel, and high intensity statin therapy. One patient suffered an asymptomatic intracerebral hemorrhage and was found later to have amyloid angiopathy. 15.2% of patients treated in the 4.5-6 hour window recovered. Recovery was defined as visual acuity of 20/100 or better, and all patients enrolled had a visual acuity of 20/200 or worse. The recovery rate remained higher in the alteplase group even when recovery was defined as 20/60.
The investigators admit a significant limitation of the study is the lack of randomization due to the observational nature, the possibility of inclusion of people who might have spontaneously resolved without treatment, and selection bias towards treatment with alteplase. Even with these limitations, the investigators feel the study provides foundational support for a multicenter randomized trial. As someone who continues to grapple with this problem on a weekly basis, I will be anxiously waiting by the phone.
