Results of this post hoc analysis of the AREDS2 trial reveal that correlation in GA enlargement rates between fellow eyes was modest. Key GA characteristics of area, location, focality, and RPD status, as well as the transformation used, were strongly associated with the correlation. Untransformed rates were inflated by a tendency for symmetry in baseline GA characteristics, whereas genuine biological correlation (best reflected by linear enlargement) was only weak to moderate. Researchers should be cautious of trials and analyses relying on assumptions of highly correlated enlargement rates.
Emde et al. (Thu,) studied this question.