Microbiological Testing of Split-Cornea Transplantation.

PURPOSE: By splitting a donor cornea into an anterior and a posterior donor lamella, the need for donor tissue can be reduced in times of lack of donors. Current eye bank regulations limit the use of each donor cornea to one recipient. METHODS: The anterior lamella not applied to the patient after each sterile DMEK preparation performed was stored for one week and was microbiologically controlled on day 7. RESULTS: Between October 2020 and December 2021, microbiological controls of 108 consecutive anterior lamellae were performed at the Department of Ophthalmology, University of Duesseldorf, without any contamination found. CONCLUSION: Our data suggest split-cornea transplantation is a microbiologically safe procedure.

Impact of donor graft quality on deep anterior lamellar Keratoplasty (DALK).

BACKGROUND: To evaluate main features of donor tissue that may influence clinical outcome or complication rate after deep anterior lamellar keratoplasty (DALK). METHODS: Donor tissue parameters of 84 consecutive corneal donor grafts used for big-bubble DALK surgery between June 2011 and December 2014 in 84 eyes of 84 patients with disorders of anterior corneal stroma were correlated to clinical outcome parameters of recipient eyes 12 months after surgery and 3 months after total suture removal. Main donor tissue parameters included age), post-mortem time, overall preservation time, preservation time after split and prior to transplantation, and preservation technique. Clinical outcome parameters included best spectacle corrected visual acuity (BSCVA), central corneal thickness (CCT), endothelial cell density (ECD) and complication rates. Pearson's correlation, linear regression analysis for clinical outcome parameter and logistic regression analysis for postsurgical complication rates were applied. RESULTS: Corneal donors were mean aged 67.4 ± 12.5 years with a post-mortem time of 20.7 ± 14.7 h and ECD of 2641.0 ± 362.8 cells/mm2. Overall preservation time was 16.3 ± 6.3 days. Recipients showed mean BSCVA 12 months postoperatively of 0.60 ± 0.36 logMAR, endothelial cell loss was 4 ± 16%, and central corneal thickness was 571.7 ± 54.2 µm. 3 months after total removal of sutures, BSCVA was 0.20 ± 0.10 logMAR, endothelial cell loss was 17 ± 24%, and central corneal thickness was 590.9 ± 55.5 µm. Loosening of sutures occurred in 20%, and Descemet detachment in 16%. None of the clinical outcome parameters or complication rate after DALK showed a significant association with donor tissue parameters. CONCLUSIONS: Donor corneas, independent of excision techniques or preservation method, with donor age ≤ 88 years, post-mortem time ≤ 63 h, overall preservation time ≤ 14 days for cold storaged donor tissue and ≤35 days for organ culture, and preservation time after split prior to grafting ≤96 h, seem to be applicable as safe donor tissue for DALK surgery.

Four Cases of Split Cornea Transplantation from a Single Cornea

PURPOSE: To report four cases of split cornea transplantation involving separate Descemet membrane keratoplasty and Deep anterior lamella keratoplasty from a single cornea. CASE SUMMARY: Four donor corneas were separated into the endothelium and other layers. The endothelial layers were transplanted into 4 pseudophakic bullous keratopathy patients, and the other layers were stored in corneal storage media. Deep anterior lamella keratoplasties were performed with the stored corneas in 2 lipid keratopathy and 2 keratoconus patients. Postoperatively, all grafted corneas were stable. CONCLUSIONS: The authors report the first 4 cases of split cornea transplantation in Korea, which is experiencing a shortage of donated corneas. Split cornea transplantation will be of benefit to a large number of patients by separating a single cornea into separate layers to be implanted into two patients.