ATXN1 and autosomal dominant cerebellar ataxia: Of note, mRNFL is very thin and has a high intertest variability, making a significant group difference in a small sample unlikely.20, 29 Abe et al., in 1997, first reported that SCA‐ATXN1 patients showed optic nerve atrophy by fundus examination as well as color vision dysfunction and visual field abnormalities.30 An earlier study from our group in 2011,14 a study comprising several SCA genotypes by Pula et al.,13 and a recent case series by Nishiguchi et al.31 reported temporal RNFL thinning and macular neurodegeneration, respectively.