Outcomes of Penetrating Keratoplasty With Imported Corneas Compared With Local Corneas

Endothelial failure and rejection in recipients of corneas from the same donor

Objective

To determine whether patients who receive corneas from the same donor have similar risks of endothelial failure and rejection.

Methods and Analysis

Patients with Fuchs endothelial dystrophy (FED) and pseudophakic bullous keratopathy (PBK) who received their first corneal transplant between 1999 and 2016 were analysed. Patients receiving corneas from donors who donated both corneas for the same indication were defined as ‘paired’. Gray’s test was used to compare the cumulative incidence of endothelial failure and rejection within 5 years post-transplant for ‘paired’ and ‘unpaired’ groups. Cox regression models were fitted to determine whether there was an association between recorded donor characteristics (endothelial cell density (ECD), age and sex and endothelial graft failure and rejection.

Results

10 838 patients were analysed of whom 1536 (14%) were paired. The unpaired group comprised 1837 (69%) recipients of single corneal donors and 7465 (69%) donors who donated both corneas for another indication. ECD was lower for unpaired single cornea donors (p<0.01). There was no significant difference in endothelial graft failure or rejection between paired and unpaired groups for FED (p=0.37, p=0.99) or PBK (p=0.88, p=0.28) nor for donor ECD, age, sex and paired donation after adjusting for transplant factors (across all models p>0.16 for ECD, p>0.32 for donor age, p>0.14 for sex match and p>0.17 for the donor effect).

Conclusion

The absence of a significant difference in graft outcome for corneal transplants for FED and PBK between paired and unpaired donors may reflect a homogeneous donor pool in the UK.

Effect of Rho-associated kinase inhibitor on human corneal endothelial cell apoptosis

PURPOSE

To evaluate whether exposure to Rho-associated protein kinase (ROCK) inhibitor will promote human-cultured corneal endothelial cells (CECs) survival in a commercial storage medium.

SETTING

Edith Wolfson Medical Center, Holon, and Sheba Medical Center, Tel Hashomer, Israel.

DESIGN

Experimental study.

METHODS

Fragments of human donor corneolimbal rings were stored in commercial storage media for 1 week, half with the addition of 10 μM ROCK inhibitor (Y-27632). Evaluation of CECs for early and late apoptosis\necrosis rates was performed using anti-human CD166 antibody and flow cytometric double staining analysis of propidium iodide and Annexin V.

RESULTS

CECs of 6 corneolimbal rings demonstrated a reduced early apoptosis rate (4.35% ± 1.07% vs 12.18% ± 5.5%, P = .026) and a reduced late apoptosis\necrosis rate (5.5% ± 2.39% vs 9.43% ± 2.61%, P = .004) compared with control. Subsequently, the rate of apoptotic CECs expressing ROCK was significantly lower in cells exposed to ROCK inhibitor compared with cells that were not (19.01% ± 4.17 vs 30.42% ± 4.27, P < .001).

CONCLUSIONS

ROCK inhibitor reduced endothelial cell loss in vitro and might be used to limit or slow CEC loss in donor corneal tissue during eye banking. This might be a promising new method for promoting future graft survival.

Effect of Donor Cornea on the Surgical Outcomes of Penetrating Keratoplasty: Imported Cornea Versus Domestic Cornea

OBJECTIVES

In this study, we compared the surgical outcomes of penetrating keratoplasty using domestic and imported donor corneas.

MATERIALS AND METHODS

We retrospectively evaluated 200 eyes and 200 consecutive patients who underwent penetrating keratoplasty by using domestic and imported donor corneas between January 2013 and December 2013. The donor characteristics, preoperative clinical features, and clinical outcomes at 6, 12, 24, and 36 months were assessed.

RESULTS

No significant differences existed between the 2 groups with respect to age, sex, lateralization, and penetrating keratoplasty indication (P > .05). Donor age was lower (P = .012), the death-to-preservation time and the preservation-to-surgery time were shorter, the rate of epithelial defect was lower, and the endothelial cell count was higher in the domestic group (P < .001). The 2 groups were also similar in terms of developing persistent epithelial defect, glaucoma, keratitis, and graft survival (P > .05).

CONCLUSIONS

We observed no significant differences in clinical outcomes during and after penetrating keratoplasty surgery between imported and domestic donor corneas.

Management of high-risk corneal transplantation

The cornea is the most commonly transplanted tissue in medicine. The main cause of corneal graft failure is allograft rejection. The incidence of graft rejection depends on the presence of high-risk characteristics, most notably corneal neovascularization. Although corneal grafting has high success rates in the absence of these risk factors, high-risk keratoplasty is associated with low success rates because of a high incidence of immune-mediated graft rejection. To improve the survival of high-risk corneal transplantation, various preoperative, intraoperative, and postoperative measures can be considered; however, the key step in the management of these grafts is the long-term use of local and/or systemic immunosuppressive agents. Although a number of immunosuppressive agents have been used for this purpose, the results vary significantly across different studies. This is partly due to the lack of an optimized method for their use, as well as the lack of a precise stratification of the degree of risk in each individual patient. New targeted biologic treatments, as well as tolerance-inducing methods, show promising horizons in the management of high-risk corneal transplantation in near future.