Alterações visuais assintomáticas na esclerose múltipla

Abstract

Introduction: Visual dysfunction is one of the most common causes of disability in multiple sclerosis (MS). Careful examination of MS patients, who have never suffered optic neuritis (ON), may reveal asymptomatic visual loss. Objective: To investigate the frequency and characteristics of asymptomatic visual loss of MS patients with the aim of identifying the most common types of asymptomatic visual loss and any correlated factors. Methods: Visual acuity; contrast sensitivity; color vision and visualfield were performed in 69 patients with clinically defined MS (40 visuallyasymptomatic and with no previous history of ON, and 29 who had already had ON). Controls were healthy individuals matched for age and sex. Results: Contrast sensitivity was abnormal in 72,5% of patients at 1,25% contrast chart, 67,5% at 0,6% and 41,3% at 5% contrast chart; followed by color vision (abnormal in 68,8%) and visual field (abnormal in 61,5%). All the visual function tests results were better in patients with no previous history of ON, compared to the group with previous historyof ON (p < 0,01). Asymptomatic visual dysfunction was correlated to the gender, disease subtype, age at onset of the disease and EDSS. Conclusion: Visual loss occurs in visually asymptomatic MS patients. Contrast sensitivity it was the most precociously affected visual function in MS, followed by color vision and visual field. In our sample, female gender, progressive subtype of disease, higher age at onset ofthe disease and high level of disability as measured by EDSS score predicted the visual loss in visually asymptomatic MS patients. To the best of our knowledge this is the first report on the study of asymptomatic visual dysfunction in a sample of MS patients that involved simultaneous analysis of contrast sensitivity, color vision and visual field.