Historical, Diagnostic, and Chromatic Treatment in Visual Snow Syndrome: A Retrospective Analysis

Abstract

SIGNIFICANCE:Visual snow syndrome is a relatively new medical condition, with presence of visual snow as the primary visual-perceptual symptom. Information from the present study will improve future clinical diagnostic and treatment aspects in this population.PURPOSE: This study aimed to determine the historical, diagnostic, and treatment aspects in patients with documented visual snow syndrome/visual snow in an academic, optometric setting.METHODS: A retrospective analysis was performed in patients (N = 40, aged 12 to 55 years) with documented visual snow syndrome/visual snow examined over a 4-year period. Information was collected by a detailed case history and the Visual Snow Syndrome Symptom Survey. Treatment assessment was performed using the Intuitive Colorimeter, and a wide selection of chromatic tints was assessed under the most provocative/exacerbating and other conditions. RESULTS: Visual snow was typically constant and monochromatic, with it being present on average 6.43 years. Bright and dark surfaces were the most provocative/exacerbating/revealing conditions, along with the viewing of computer screens. The most common etiology was mild traumatic brain injury. The most common primary and secondary symptoms were photosensitivity and tinnitus, respectively. There was a high frequency of occurrence of oculomotor deficits, especially accommodative and vergence insufficiency (~40 to 50%). Eighty percent of the patients were prescribed a chromatic tint with subjective visual reduction of visual snow ranging from 15 to 100% (mean, 45%). CONCLUSIONS:The present information will help in understanding this unusual medicoperceptual condition, especially with respect to simple treatment frequently using readily available chromatic tints.

Clinical reading-related oculomotor assessment in visual snow syndrome

“…The findings of the present retrospective study confirmed and extended those of earlier investigations 4 , 5 , 6 , 7 , 8 : individuals with VSS manifest a wide range and high prevalence of oculomotor-based dysfunctions and related reading problems. For example, in a recent clinically-based, retrospective study, 4 nearly all (96 %) of the 27 patients diagnosed with VSS exhibited a binocular vision/oculomotor problem: 59 % had a versional deficit (i.e., general oculomotor dysfunction, OMD), 53 % had convergence insufficiency, 33 % had convergence excess, and 54 % had accommodative insufficiency.…”

“…Over the past three years, there have been clinical 4 , 5 and laboratory 6 , 7 , 8 studies demonstrating an unusually high frequency of oculomotor deficits in VSS. In the clinical studies, up to 60% of the patients manifested common oculomotor diagnoses, such as convergence insufficiency, accommodative insufficiency, and general oculomotor dysfunction (OMD) (e.g., saccadic dysmetria).…”

Visual snow syndrome: recent advances in understanding the pathophysiology and potential treatment approaches

“…A retrospective analysis of 40 patients with VSS identified a high frequency (up to 50%) of occurrence of oculomotor deficits such as accommodative insufficiency, convergence insufficiency and saccadic deficits [ 30 ]. Another retrospective study also showed a very high rate (26/27 patients) of comorbid binocular abnormalities in the VSS population such as oculomotor dysfunction (OMD) (59.3%), convergence insufficiency (51.9%), and accommodative insufficiency (54.5%) among other eye movement disorders [ 31 ].…”

“…A retrospective analysis of 40 individuals with VSS found that the use of tinted glasses, particularly those that reduce transmission in the blue range of the visible spectrum, reduced the perceived intensity, duration, and frequency of visual snow in 80% of patients [ 30 ]. These tints may have a dual effect by reducing overall luminance and further reducing luminance due to the chromatic distortion of the filter.…”

“…These tints may have a dual effect by reducing overall luminance and further reducing luminance due to the chromatic distortion of the filter. The tinted glasses were also effective in reducing other related visual symptoms such as palinopsia or entoptic phenomena and could be incorporated into glasses correction or used as clip-ons [ 30 ].…”