The learning curve for Descemet membrane endothelial keratoplasty performed by two experienced corneal surgeons: a consecutive series of 40 cases

PURPOSE: To describe the learning curve for Descemet's membrane endothelial keratoplasty (DMEK) in the Rotterdam Eye Hospital and to evaluate safety and visual outcome.

METHODS: This was a single-centre prospective study of 40 consecutive patients with Fuchs' endothelial dystrophy who underwent a DMEK procedure in the Rotterdam Eye Hospital. The performance of two corneal surgeons, each conducting their first series of 20 procedures, was examined with the cumulative summation test for the learning curve (LC-CUSUM). The surgical procedure was considered unsuccessful when >30% of the graft was not attached at any time during the first 12 postoperative weeks and a mixture of SF6 (20%) and air (80%) had to be injected in the anterior chamber (rebubbling) to reattach the graft. Also assessed were visual outcome, intraocular pressure and peri- and postoperative complications.

RESULTS: In total, nine rebubbling procedures were performed in seven eyes. Following repeated rebubbling, two eyes did not achieve a satisfactory result and secondary surgery was required to restore visual function. Complications were usually manageable. The last 13 DMEK procedures (33%) of this series did not require rebubbling. After 3 months, 86% of the eyes had reached a Snellen visual acuity of 0.5 or more.

CONCLUSION: Together with the two surgeons' personal experience, the aggregate learning curve was considered to justify incorporation of Descemet membrane endothelial keratoplasty as a regular option of the standard of care for endothelial dysfunction in the Rotterdam Eye Hospital.