Modified pre-descements endothelial keratoplasty (PDEK) and the effect of using Viscoat® in minimizing endothelial cell loss during tissue preparation

Abstract

Objective: To prepare large sized Pre-Descemet’s endothelial keratoplasty (PDEK) lenticule with stromal (PDEK-S) and to assess the effect of using Viscoat® in   minimizing endothelial cell loss during its preparation.

Methods: Paired corneas were randomly assigned for Pre-Descemet’s endothelial keratoplasty (PDEK) donor lenticule preparation in two groups depending on the application of Viscoat. Type-1 air bubble was formed with a 30-gauge needle, bevel up with a 3-cc volume syringe. Stromal tissues were excised from the periphery. The percentage of endothelial cell loss before and after dissection was estimated with Trypan blue Photo.

Results: A total of 20 paired eyes were used. The average donor age was 57years. A 15% of endothelial cell loss induced by the preparation process was observed in both groups. The percentage of Endothelial Cell Loss was not significantly associated with the use of Viscoat during preparation (p - 0.87). We observed that larger diameter donor lenticules were associated with younger donors (p- 0.028). The largest diameter of Pre-Descemet’s endothelial keratoplasty (PDEK) lenticule was 9.5mm.

Conclusion: The use of Viscoat as an endothelial shield during Pre-Descemet’s endothelial keratoplasty (PDEK) donor lenticule preparation has no significant effect in reducing the percentage of endothelial cell loss. The size of Pre-Decrement’s endothelial keratoplasty (PDEK) donor lenticule can be increased by adding thin stroma at the periphery (PDEK-S). PDEK-S allows the utility of corneas from younger patients for endothelial keratoplasty, and Younger aged donors are associated with larger sized donor lenticules.