LAUSR

To the Editor: We read with great interest the study by Pasari et al1 in which they evaluated visual outcomes and graft survival of Descemet membrane endothelial keratoplasty for failed penetrating keratoplasty. We would like to congratulate them for a very wellconducted study. However, there are a few points that we want to highlight for better understanding. The authors have reported the number of clear grafts at 1, 2, 3, and 4 years of follow-up as 69, 41, 26, and 12, respectively. The percentage for the same would have been a better understanding tool because all the cases were not available for all follow-ups. The 5 grafts with early failure had repeat endothelial keratoplasty performed, of which 2 were Descemet membrane endothelial keratoplasty. The authors did not mention whether they have included these 2 cases in the analysis. Two eyes with aqueous shunts and previous trabeculectomy had late failure. Reasons for late failure are imbalance in aqueous proteins and change in corneal endothelial microenvironment, as stated by Rosenfeld et al.2 We want to point out that malpositioning of the shunt in the anterior chamber can also be one of the reasons for graft failure in these cases. It would have been better if the authors mentioned positioning of the shunt in these cases.