Short Axial Length and Iris Damage Are Associated With Iris Posterior Synechiae After Descemet Membrane Endothelial Keratoplasty in Asian Eyes

Purpose: To evaluate the frequency and severity of iris posterior synechiae after Descemet membrane endothelial keratoplasty (DMEK) and to investigate possible causes of iris posterior synechiae. Methods: Twenty-three eyes were investigated in 20 Asian patients who underwent DMEK 1 month after phacoemulsification and intraocular lens implantation surgery. A preexisting iris damage score was defined by iris damage and classified into 5 grades. Six months after DMEK, the iris posterior synechiae severity score was evaluated based on the extent of posterior synechiae, according to every 45 degrees of the pupillary rim (posterior synechiae score, 0–8). Correlations were analyzed between the posterior synechiae score and preexisting factors (preexisting iris damage score, axial length [AXL], anterior chamber depth, and anterior chamber volume, both before and after cataract surgery). Results: Iris posterior synechiae appeared in 20 of 23 eyes (87.0%). Best spectacle-corrected visual acuity significantly improved at 6 months after DMEK (P < 0.001). Endothelial cell density was 1596 ± 530 cells/mm2 (P < 0.001); loss of cell density was 37.8 ± 19.9% at 6 months. Single regression analysis showed that the onset of iris posterior synechiae was correlated with the preexisting iris damage score (P = 0.006, r = 0.55), AXL (P < 0.001, r = −0.71), anterior chamber depth (P < 0.001, r = −0.70), and anterior chamber volume before cataract surgery (P < 0.001, r = −0.79). Conclusions: Iris posterior synechiae after DMEK frequently appeared in Asian eyes with shorter AXLs or a damaged iris.