UK: A recent study in the British Journal of Ophthalmology has confirmed that common drug treatments are generally ineffective in visual snow syndrome (VSS). Vitamins and benzodiazepines however were shown to be beneficial in some patients and can be considered safe for this condition.
Visual snow is a primary neurological disorder consisting of a constant positive visual disturbance described as uncountable tiny dots over the entire visual field. Francesca Puledda, King's College London, London, UK, and colleagues aimed to gather information on useful medications to treat visual snow syndrome and to validate an instrument to assess its clinical severity and the course of the disorder over time.
The web-based prospective questionnaire study included 400 patients with VSS. All subjects completed a treatment questionnaire and a clinical diary. The first allowed evaluation of the effects of previous medications on visual snow, while the second measured VSS symptoms daily over the course of 30 days.
The study revealed the following findings:
Patients commonly reported previous use of medications such as antidepressants, antiepileptics, antibiotics and benzodiazepines.
None of these drug classes was beneficial for the majority of patients.
Recreational drugs and alcohol worsened visual snow symptoms in several reports.
Vitamins and benzodiazepines had high therapeutic ratios, although in most cases they did not change the course of VSS.
The monthly diary confirmed that the static in VSS is a consistent symptom over time. It also showed that indoor and fluorescent lights have a worse effect on symptoms when compared with natural outdoor lighting.
"The study confirms clinical experience that medications are generally ineffective in VSS, with the exception of vitamins and perhaps benzodiazepines, which could be beneficial in some patients," wrote the authors. "The 30-day diary represents a useful tool to measure symptom sprogression over time, which could be used in future trials on VSS."
Further studies, ideally randomised controlled trials, are needed in order to understand the full effects of medications such as benzodiazepines on VSS, they concluded.