Thickening of peripapillar retinal fibers for the diagnosis of autosomal recessive spastic ataxia of Charlevoix-Saguenay.

Autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS) is characterized by the presence of myelinated retinal fibers. This typical feature is very helpful for the diagnosis but is not always observed in patients outside Quebec. Apart from phenotype variations, misinterpretation of the funduscopy may explain discrepancies and misdiagnosis.