Visual snow: a neuro-ophthalmic syndrome

Abstract

Background: The visual snow syndrome (VSS) is a rare disease characterized by persistent positive visual phenomena that are enigmatic and may be underestimated. It manifests as the perception of tiny, simultaneous, diffuse, and mobile dots frequently throughout the visual field. Although it affects brain networks, ocular examination is also indicated. This paper was aimed to review recent studies on VSS to identify the best clinical approach.
 Methods: In this narrative review, PubMed/Medline, Directory of Open Access Journals, and Embase were searched using the following terms: “Visual snow”, “Persistent aura”, “Persistent positive visual phenomena”, “Visual aura”, “Migraine”, “TV static”, “Migraine aura status”, and “Visual disturbance”. We searched relevant publications from January 2014 to January 2021 to find the best clinical approach. 
 Results: VSS may be reconstituted as a distinct entity, although the symptoms may be consistent with typical migraine visual aura. For approximately two-thirds of patients, symptoms worsen and reduce their ability for activities of daily living. It often causes psychogenic detriment of the patient and their capacity to function socially and vocationally. Comprehensive history-taking and ocular examination are required to rule out other causes. However, all ocular and radiological findings may be normal. 
 Conclusions: VSS is a neuro-ophthalmic disorder characterized by continuous chronic and recurrent visual disturbances that involve the entire visual field and may respond to empiric antimigraine or anti-seizure treatments. It may reduce the ability for activities of daily living; therefore, proper diagnosis by eye care professionals is necessary to determine its diagnosis and management.