Czech and Slovak Ophthalmology 179 10.31348/2020/38 Case report Can Visual Function Be Affected by an Open Foramen Ovale? Výborný Petr Čmelo Jozef 25 1 2021 6 5

The authors present a relatively rare finding of pathological changes in the visual field, the emergence of homonymous hemianopia, in connection with trauma and paradoxical embolism in a subsequently diagnosed open foramen ovale in a 56-year-old otherwise healthy patient. Cardiac source of embolism is a significant etiology of vascular embolization. The important group is the so-called paradoxical embolism, which occurs when a blood clot (embolus) is carried from the venous side of circulation to the arterial side via foramen ovale patens, what can manifests as ischemic stroke. Foramen ovale patens becomes a risk factor for the stroke development only if there is a peripheral source of embolism and at the same time there is a hemodynamically significant right-left short circuit. Therefore, screening for the causes of cryptogenic stroke should include not only the detection of foramen ovale patens but also evaluation of the peripheral venous system, coagulation parameters and hemodynamic severity of a right-left shunt. Neuroophthalmological aspects related to the described issues are discussed.

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