Natural course of Visual Snow Syndrome: a long-term follow-up study

Abstract

Background and aims: Visual Snow Syndrome (VSS) is characterized by a continuous positive pan-field visual disturbance resembling the view of a badly-tuned analogue television plus associated visual symptoms. For many patients VSS can be disabling. We present the 1st longitudinal study describing the long-term natural course of the disorder over 8 years.

Methods: In total 78 Patients with confirmed VSS, including normal ophthalmologic exams, were followed from November 2011 to December 2019. The clinical course of the disorder was assessed in a semi-structured telephone interview.

Results: 40 of 78 (51%) patients were reached for the follow up interview. Mean follow up time was 83.6±4.5 months. 2 of 40 (5%) reported the onset of additional visual symptoms, which were tunnel vision and light flashes. Compared to 2011, less patients rated visual snow itself as the most disturbing symptom (40% in 2019 vs 72.5% in 2011, p=0.001); instead, patients suffered more from floaters and palinopsia. New treatments were commenced in 14/40 (35%) patients. Of those, 6 (42%) were somewhat helpful: lamotrigine, diet/vitamin supplements/probiotics, lorazepam, cinnarizine, polarized glasses, chiropractic treatment. During follow up, 3 patients experienced new visual migraine aura without headache, and one had new migraine headache (total prevalence aura 35%, migraine 47.5%). There was no significant difference in anxiety and depression measured by the PHQ-8 and the GAD-7 questionnaire.

Conclusion: In a group of patients with VSS, symptoms can persist over 8 years without spontaneous resolution. New visual symptoms can develop, but visual snow itself might get less bothersome.

Disclosure: Nothing to disclose