We read with interest the letter by Hwang et al.,
1 titled “A meta-analysis of glaucoma risk in hyperlipidemic individuals: a critical problem in design,” which was written in reply to our recent publication.
2 We would like to thank the authors for their response and the additional information it provides.
We agree with Hwang et al.
1 that a potential flaw in our study was that we could not fully ascertain if it was statins or hyperlipidemia that reduced the risk of glaucoma or if the effects of hyperlipidemia reduced the observed effect of statins (confounding by indication). Hwang et al.
1 have attempted to answer if hyperlipidemia affects the risk of glaucoma. However the included studies in their analysis “…did not refine the effects of hyperlipidemia from those of lipid-lowering drugs.” This is a similar limitation to the one faced in our study. We therefore agree that the effect sizes in both our meta-analyses potentially could be underestimated.