Bilateral Acute Orbital Protrusion During Lysis-Therapy In Myocardial Infarction - A Rare Case

A 51-year-old male patient with circulatory arrest and ventricular fibrillation was brought to the emergency department after restoration of spontaneous circulation ECG presented signs of an acute anterolateral myocardial infarction. Thrombolytic therapy according to the Neuhaus scheme was initiated. After administration of 60 mg rt-PA continuously increasing protrusion and hyposphagma of both eyes (left > right) and left-sided monocle-hematoma was observed. CCT showed shadowing of sinus ethmoidales and frontales, broadening of the left lateral rectus muscle and retrobulbar volume increase without any signs of recent bleeding.The ophthalmologist had to answer the question if there was, in spite of the massive retrobulbar volume increase, a sufficient blood supply for both eyes. Ophthalmoscopically there were no signs of intraretinal bleeding or retinal ischemia.Intraocular circulation was checked by color Doppler sonography: Ophthalmic artery, the short posterior ciliary arteries and central retinal artery of both eyes showed very low, but definitely positive bloodflow. Further course showed a constant trend towards higher systolic bloodflow velocities in all eve vessels, verified by color Doppler sonography.Computer perimetry, performed after the recovery of the patient, revealed a visual field defect, which was related to a breakdown of the flow in a ciliary artery rather than to damage due to compression of the optic nerve.Possible reasons of the retrobulbar volume increase under thrombolytic therapy are discussed.