Clinicopathology of graft detachment after Descemet's membrane endothelial keratoplasty

Abstract

ABSTRACT.Purpose: To investigate pathomechanisms involved in graft detachment after Descemet's membrane endothelial keratoplasty (DMEK) and its clinical implications. Methods: In a prospective case series, 30 eyes with Fuchs' endothelial dystrophy underwent DMEK. Intraoperatively obtained recipients' endothelium-Descemet's membranes (EDMs) were investigated histologically and immunohistochemically. The postoperative donor graft status was categorized as attached or detached. Clinical and morphological parameters were analysed between the study groups. Results: The detachment rate was 40% (12/30). There was no significant difference in postoperative visual acuity between the groups, but visual recovery was delayed in eyes with initially detached grafts. Gender, age, preoperative central corneal thickness or best corrected visual acuity did not influence the detachment rate. However, separation and disruption of the anterior banded layer (ABL) were frequently observed in patients with graft detachment, and ABL thickness was identified as a significant predictor for graft detachment. The ABL thickness was 2.5 AE 0.9 lm and 3.5 AE 1.6 lm in patients with attached and detached grafts, respectively. Immunohistologically, a deficiency of fibronectin and cytokeratin was observed within the ABL of patients with detached grafts. In contrast, a complete removal of the EDM with residual stromal collagen fragments was observed in patients with adherent grafts. Conclusions: Incomplete removal of the EDM, with residual ABL fragments on the recipients' corneal stroma, may be a risk factor for graft detachment after DMEK. The separation and disruption of the ABL might be promoted by a deficiency of matrix proteins, stronger biomechanical properties and a firm adherence to the posterior corneal stroma.

Ultrahigh-resolution OCT imaging of the human cornea

“…After DMEK, the literature reports a re-surgery rate of approximately 5%, caused by graft failure or detachment [81][82][83]. Graft detachment has been identified as the main complication following DMEK occurring in up to 40% of patients after surgery [84,85]. Some surgeons treat this complication by inserting air in the anterior chamber ("rebubbling") in order to achieve reattachment of the graft.…”

Descemet membrane endothelial keratoplasty

“…An adequately sized descemetorrhexis may be important for graft attachment in order to reduced overlap between donor and recipient DM, which may cause donor lift-off in the periphery (unlike DSEK where the stripping diameter is often smaller than the donor) 42. The use of trypan blue 0.06% staining in the recipient after stripping the DM can be useful to ensure complete DM removal as residual fragments of the anterior banded layer of the host DM have been associated with a higher risk of detachments 43. As it is believed to reduce graft adherence, avoidance of viscoelastics during the recipient preparation has been advocated, although some surgeons report the safe use of cohesive viscoelastics as long as it is thoroughly removed before donor insertion 44 45…”

Descemet-Membran-Endothelkeratoplastik (DMEK)

“…"Descemet-Inseln" werden in bis zu der Hälfte der Fälle beobachtet und sollten auf jeden Fall komplett entfernt werden. Sie können nämlich negativen Einfluss auf das Visusergebnis sowie auf die Adhärenz des Transplantats haben und sind mit einem erhöhten Risiko für eine Transplantatablösung verbunden [31,32].…”

“…In der Patientenkohorte der Autoren wurde nur bei klinisch signifikanter Transplantatablösung ein Rebubbling indiziert, was bei insgesamt 14 % aller Fälle notwendig war [46]. Zu den Risikofaktoren, welche für eine Transplantatablösung prädisponieren, zählen eine inkomplette Entfernung der Empfänger-Descemet-Membran mit zurückbleibenden "Empfänger-Descemet-Inseln" [31,32], ein Überlappen von Empfänger-und Spender-Descemet-Membran bei zu klein geratener Descemetorhexis oder dezentriertem Transplantat [33], eine insuffiziente Tonisierung und Luftfüllung am Ende der Operation (z. B. bei alterierten anatomischen Verhältnissen wie in vitrektomierten oder aphaken Augen) [58] oder wenn die Compliance des Patienten hinsichtlich der postoperativen Rückenlagerung reduziert ist.…”