To the Editor Musch1 is to be applauded for his insightful editorial that highlights the major challenges that can be faced by clinicians when attempting to apply evidence-based medicine to the complex domain of nutritional supplementation and age-related macular degeneration (AMD). In particular, this editorial discusses the outcomes of the Age-Related Eye Disease Study (AREDS)2 and AREDS23 clinical trials and the need for the appropriate application of their findings to clinical practice. We wish to highlight an additional noteworthy aspect of these studies. The results of AREDS2, being much anticipated although surprising, balance the primary results with fascinating exploratory analyses. In particular, we were intrigued to observe that each of the primary randomization groups showed higher progression rates to advanced AMD than the same subgroup from the original AREDS clinical trial2 (ie, 29%-31% compared with 20% for categories 3 and 4); notably, these progression rates were also higher than even the control (no treatment) group in AREDS (28%). We understand that this apparent divergence in findings can be accounted for through adjustments for age and disease severity (Frederick L. Ferris III, PhD, written communication, November 6, 2013); however, these observations highlight the challenges that can be faced when comparing clinical trial data from different studies.
Downie LE, Keller PR. Making Sense of the Evidence From the Age-Related Eye Disease Study 2 Randomized Clinical Trial. JAMA Ophthalmol. 2014;132(8):1031. doi:10.1001/jamaophthalmol.2014.2007