Pre-Descemet's Endothelial Keratoplasty (PDEK): Learning Curve in the First Brazilian Cases

Abstract

Emilio Almeida Torres-Netto, Maria Daniela Rivera-Monge, Denise de Freitas and Aline Moriyama

Purpose: To describe the learning curve of pre-descemet endothelial keratoplasty (PDEK) and the intraoperatory findings of the first 5 cases performed at Federal University of Sao Paulo. Methods: Five PDEK procedures were performed by the same surgeons; four cases used pneumodissection and one case used reverse hydro-bubble technique to obtain the donor graft. All cases were recorded and the following intraoperative variables were measured: type of bubble obtained, button size used and time of opening and centralization of the graft in the recipient anterior chamber. Results: Type-1 Big Bubble (BB) was achieved in three of the four cases that air dissection was used. In the fourth case of pneumodissection, there was simultaneous formation of type-1 and type-2 BB. When balanced saline solution was used for dissection, type-2 BB was obtained. Every time type-2 BB was formed, the procedure was then converted to Descemet Membrane Endothelial Keratoplasty (DMEK). When only type-1 BB was achieved, the PDEK was uneventful with an easier, manipulation of the tissue and a quicker opening in the recipient anterior chamber. Namely, grafts that included pre-Descemet’s layer were less elastic and less curled. The graft size used varied from 7.50 to 7.75mm. Conclusion: PDEK is a recent technique of endothelial keratoplasty. Early outcomes suggest potential advantages in the learning curve over the prior procedures, especially by the facilitated manipulation of PDEK graft in the anterior chamber. Although results with this technique seem promising, the potential advantages need to be confirmed with long-term postoperative follow-up.

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