Ocular Findings and Clinical Observations in Patients With Spinocerebellar Ataxia Type 3 (SCA3)

Abstract

Abstract: : Purpose: The objective of the study was to describe ophthalmic findings in patients diagnosed with SCA3, an autosomic dominant cerebellar ataxia caused by triplet repeat mutation. Methods: Retrospective review of charts of 15 patients with SCA3 disease gene expansions. Ocular examination included visual acuity, color vision (Farnsworth D15), visual fields, intraocular pressure, stereo acuity, ocular motility, slit lamp examination and fundus exam.Results: Total of 15 patients were examined. Age ranged from 26-61 years (average 43 years). Six (40%) were females, 9 (60%) males, 11 (73%) African-Americans, 4 (27%) Caucasians. Seven (47%) had no visual symptoms, 7 (47%) complained of diplopia and 1 (6%) complained of decreased vision. Visual acuity was 20/25 or better in all patients. Ten African-American patients (67%) had acquired color vision abnormalities. One (6%) 26-year-old African-American and 4 (27%) Caucasians patients had normal color vision. Ocular motility was abnormal in 7 (47%), and 10 showed gazed-evoked-nystagmus. Also 7 (47%) had abnormal stereo acuity. Fundus exam was normal in all patients. Conclusions: Although visual acuity is preserved in SCA3, acquired color vision abnormality may indicate sub-clinical macular dysfunction. Also, the higher prevalence of color abnormality in African-Americans may indicate racially different expressivity.

Keywords: color vision • neuro-ophthalmology: diagnosis • retina