Safety Audit For Corneal Transplantation During Transition From National To International Procurement At A Tertiary Level London Hospital

This audit aimed to contemporaneously assess the safety of corneal transplants during the Western Eye Hospital’s (WEH) transition from national to international corneal graft tissue procurement. Rates of adverse events such as graft rejection, failure, and rebubble were assessed, alongside visual acuity outcomes and any logistical challenges faced. 

The United Kingdom (UK) has suffered from long-standing lack of corneal transplant material, with an estimated 7000 people on the UK Transplant waiting list. The corneal department at WEH has recently overseen the transition from procuring UK transplant tissue to international procurement from the USA, to reduce waiting times to surgery and ultimately improve patient care. 

The study analysed 27 corneal grafts (10 DMEK, 11 DSAEK/DSEK, 6 PK) performed between October 2023 and January 2024. Fuch’s Endothelial Dystrophy was the commonest surgery indication (n=12). Follow-up data was available for 26 patients between 1 month and 3 months post-operatively; 1 patient (DMEK) was lost to follow-up. Information was collected on transplant indication, baseline donor and recipient characteristics (age, gender, visual acuity (VA), co-morbidities), transplant quality (time from tissue retrieval, cell density), serious adverse reactions, operative complications, post-operative visual acuity and complications. Logistical issues related to international procurement, including delivery delays, were also examined. 

Median recipient age was 66 (14F, 13M), with glaucoma (n=7) being the commonest ocular co-morbidity. Median donor age was 69 for DMEK (range 54-75), 68 for DSAEK/DSEK (range 30-77), and 27 for PK (range 19-67). Median time from donor retrieval was 7 days (range 5-13); mean endothelial cell count was 2841 (range 2320-3344). 26 cases were uncomplicated intraoperatively. 5 of 20 (25%) endothelial grafts needed rebubbling. Of 3 graft rejections, 2 resolved medically and 1 later developed failure (DSAEK (9%)). 16 of 26 patients with VA data at 1 month had best-corrected VA (BCVA) improve by at least 1 line; 6 saw no change and 4 worsened. Pre-operative graft quality was sub-optimal in 3 cases (2 reduced graft clarity, 1 multiple stress lines). 

Overall graft survival was 96%, similar at 3 months to literature standards (95-96%). DMEK rebubble rate was 22% (literature range 0.2-76%) and 27% in DSAEK (literature range 0%-82%). Rejection rate was 11% in DMEK and 18% in DSAEK/DSEK, with literature ranging from 0.7-5% and 5-12% respectively. No serious adverse events or other post-operative complications were observed. Delivery delays affected 3 grafts, causing surgical cancellations. The audit results have helped demonstrate an evidence-base for safety during transition from national to international corneal transplant procurement. The audit highlights the need for improved delivery processes to minimise corneal transplant tissue wastage and last-minute surgical cancellations.