Clinical Outcomes of DMEK Comparing Endothelium-Out Injector and Endothelium-In Pull-Through Techniques in Asian Eyes

Ezekiel Ze Ken Cheong ^1* Clarissa Ng Yin Ling ² Qiu Ying Wong ^2,3 Chloe Si Qi Chua ^2,3 Hla Myint Htoon ^1,3 Marcus Ang ^1,2,3*

• ¹ Ophthalmology and Visual Sciences Academic Clinical Programme, Duke-NUS Medical School, Singapore, Singapore
• ² Singapore National Eye Center, Singapore, Singapore
• ³ Singapore Eye Research Institute (SERI), Singapore, Singapore

A prospective interventional study of 180 consecutive Descemet membrane endothelial keratoplasty (DMEK) cases, comparing injector (endothelium-out) and pull-through (endothelium-in) surgical techniques in Asian eyes. Main outcome measures were 5-year graft survival, intra-operative and post-operative complications. In our study, pullthrough technique for DMEK was employed more frequently in PBK (66.2%) than FECD (10.7%) eyes (P < 0.001). Overall five-year graft survival was 90% (98% in FECD and 64% in PBK eyes; P < 0.001). We observed higher rates of intraoperative donor graft tears (6.5% vs 0.8%; P = 0.049) and persistent post-operative corneal edema (19.4% vs 6.8%; P = 0.022) in pull-through-DMEK than injector-DMEK. However, multivariable analysis suggested that surgical technique was not a significant factor associated with graft survival i.e. PBK as the surgical indication was the main factor associated with graft failure (hazard ratio = 12.5; P < 0.01) and post-operative complications (odds ratio = 4.41; P < 0.01), regardless of surgical technique used. In our Asian study cohort, both injector (endothelium-out) and pull-through (endothelium-in) surgical techniques for DMEK had comparable clinical outcomes, when adjusted for confounders.