were either not affected by alcohol or not reproducible in both cohorts, as several studies have failed to find an effect of alcohol on saccade accuracy (Blekher et al. 2002a, b; Lehtinen et al. 1979; Moser et al. 1998; Vassallo and Abel 2002; Vorstius et al. 2008) and HD may display some tolerance on this measure (Roche and King 2010). Therefore, saccade accuracy may not be a sensitive measure for detecting impairment in HD. Complicating the matter, anti-saccade measures had larger variability than pro-saccade measures, which may partially account for the lack of replication for anti-saccade velocity.
