Local Immunosuppression in Wuzhishan Pig to Rhesus Monkey Descemet’s Stripping Automated Endothelial Keratoplasty: An Innovative Method to Promote the Survival of Xenografts

Abstract

Corneal xenotransplantation is an effective solution for the shortage of human corneas. We investigated the feasibility and efficacy of different postoperative protocols on xeno-Descemet's stripping automated endothelial keratoplasty (DSAEK) grafts. Thirty rhesus monkeys were randomly divided into three groups: control group (C), only Descemet's membrane (DM) stripping; DSAEK 1 (D1) and DSAEK 2 (D2) groups, DM stripping followed by endothelial keratoplasty. Betamethasone 3.5 mg was subconjunctival injected in groups control and D1 postoperatively, while animals in group D2 were treated with topical 0.1% tacrolimus and topical steroids. All groups were evaluated by slit-lamp microscopy, anterior segment OCT and LSCM for at least nine months. A total of 24 monkeys (24 eyes) met the inclusion criteria. Nine months after DSAEK surgery, all xenografts showed good attachment, and most corneas were transparent. Graft rejection occurred in 25% of the cases in group D1 and 28.57% of those in group D2 (P > 0.05). The corneal endothelium density in the DSAEK groups was 2715.83±516.20/mm² (D1) and 2220.00 ± 565.13/mm² (D2) (P > 0.05). Xenogeneic corneal endothelial grafts can survive and function in rhesus monkey eyes for a long time with subconjunctival steroid or topical tacrolimus and steroid treatment.