Ocular changes in patients with spinocerebellar degeneration and repeated trinucleotide expansion of spinocerebellar ataxia type 1 gene

Objective: To examine ocular changes in patients with spinocerebellar degeneration who have repeated trinucleotide expansion in the spinocerebellar ataxia type 1 (SCA1) gene. Design: Ophthalmic findings in 6 patients from 3 families whose DNA analysis revealed that they had an expanded allele of the trinucleotide repeated in the SCA1 gene were compared with those of normal control subjects and other healthy family members. The DNA was extracted from peripheral blood lymphocytes of the neurodegenerative family and normal control subjects. Setting: University medical center. Results: Visual acuity gradually decreased in successive follow-up visits. Color vision and visual fields were gradually affected. Electroretinograms showed mild attenuation of oscillatory potentials. Corneal endothelial cell density was severely decreased from 600 to 1300 cells/mm(2). These findings were not observed in the normal control subjects, other healthy family members, or other patients with spinocerebellar degeneration who had repeated trinucleotide expansion of other genes. Conclusion: To the best of our knowledge, this is the first report describing the association between ocular changes in patients with spinocerebellar degeneration and gene mutation. These ocular changes were considered specific to patients who had the expanded allele of the repeated trinucleotide in the SCA1 gene.