• Clinical Trial
• Retina
• Imaging
• Macula

I would like to thank Comyn et al for their interest in our published article.1 I agree that different methodologies, different assumptions, or even analyses on different patient collectives might result in a different conclusion or a different sample size needed for randomised clinical trials.

(i and ii) Power: the sample size calculation used with power of 80% was based on studies, such as the Age-Related Eye Disease Study trial.2 Using 90% power, α=0.05 and 10% loss to follow-up, I calculated once more the sample size needed for hypothetical studies (table 1).

(iii) I integrated the findings from Comyn …