Characteristics of visual snow syndrome in Japan and its association with migraine.

ObjectiveVisual snow syndrome (VSS) is closely linked to migraine and involves variable visual disturbances. The present study aimed to investigate the associations between VSS and migraine, as well as VSS and anisometropia.MethodsWe studied 148 patients with VSS (54 males and 94 females, mean age 30.0 years) and 157 control participants. The mean and difference between left and right spherical equivalent refractive values, as well as the presence of migraines, were compared in patients with VSS and healthy controls. Multivariable logistic regression analyses were performed to assess the association between migraine and symptoms (palinopsia, entoptic phenomena, nyctalopia, photophobia, hyperesthesia and tinnitus) in patients with VSS.ResultsPatients with VSS exhibited a greater difference in left and right spherical equivalent refractive values and a higher prevalence of migraine compared to controls. Logistic regression analyses revealed a significant association between migraines and palinopsia. During the follow-up period, we observed spontaneous improvement in symptoms in 10 patients.ConclusionVSS is closely associated with migraine, and anisometropia was more frequent in VSS. The high prevalence of VSS in young individuals may reflect the age-related decline in migraine prevalence.