Evaluation for Descemet Membrane Endothelial Keratoplasty in Failed Penetrating Keratoplasty

Background: Over the past decade, Penetrating Keratoplasty (PKP) graft failure has been increasingly managed by Descemet Membrane Endothelial Keratoplasty (DMEK).Moreover, Anterior Segment Optical Coherence Tomography (AS-OCT) is becoming an essential modality for perioperative evaluation.Our aim is to share important surgical considerations and modifications based on preoperative evaluation using AS-OCT and, consequently, present our clinical and surgical outcomes of DMEK performed for secondary PKP graft failure.Methods: A retrospective review of medical records was performed for patients who underwent DMEK due to failed PKP .Collected data included demographic characteristics, PKP graft size measured by AS-OCT, corneal donor endothelial cell density (ECD), intra-operative surgical method adjustments, postoperative complications, visual acuity in Snellen (VA), central pachymetry and postoperative ECD.Results: 16 patients (9 males) and 16 eyes were included.The study period was 18 months.Mean age at performing DMEK was 63 years.All patients underwent preoperative AS-OCT and case-based surgical plan was obtained.Before DMEK, mean VA and central pachymetry were 0.04 and 685 m, respectively.At last follow up, they significantly improved to 0.3 (p-value = 0.001) and 542 m (p-value = 0.008) respectively.Postoperatively, 93.75% of the grafts were attached.Graft failure rate was 6.25% due to late decompensation.Graft detachment rate and rebubbling rate were 18.75% respectively.Conclusion: A suitable case-based preoperative evaluation by AS-OCT may play a vital role in DMEK for failed PKP.Consequently, it utilizes obtaining a suitable surgical plan which may increase success rates and decrease complications rates along with accelerating visual recovery.