Cytomegalovirus infection is not a major cause of corneal graft failure in the United Kingdom.

BACKGROUND: Cytomegalovirus (CMV) endotheliitis is a significant cause for acute corneal allograft rejection in East Asian populations, where there is a high CMV seroprevalence. To determine how frequently CMV is associated with corneal graft failure in the UK, we looked for the presence of CMV DNA in grafts that had failed and had been removed at repeat keratoplasty. We also looked for CMV DNA in corneal rims discarded after corneal transplantation. METHODS: In this retrospective study, we identified 54 cases of corneal graft failure following endothelial rejection and 38 control grafts that had failed without a history of endothelial rejection. For these groups archived formalin-fixed paraffin-embedded (FFPE) tissue samples were retrieved. We also prospectively examined 80 non-fixed cornea rims following transplantation surgery. In all samples nested quantitative PCR was used to identify CMV, herpes simplex virus (HSV) and varicella zoster virus (VZV) DNA. We also used in situ hybridisation to examine for CMV DNA in the FFPE samples. RESULTS: No CMV or VZV DNA was detected in any of the archived case or control FFPE tissues. One corneal rim from the control group was positive for HSV. In situ hybridisation for CMV was negative for CMV in all FFPE samples. No CMV, VZV or HSV DNA was detected in the donor corneal rim samples. CONCLUSION: CMV DNA was not identified in excised failed corneal tissue or from tissue prior to transplantation. We infer that CMV infection is not a significant factor risk for corneal graft failure in the United Kingdom.

Fungal infection after endothelial keratoplasty: association with hypothermic corneal storage.

PURPOSE: To compare the incidence of fungal infection after endothelial keratoplasty (EK) when donor tissue had been stored in hypothermic medium or organ culture. METHODS: We describe the clinical features of 10 cases of fungal infection (keratitis or endophthalmitis) following EK identified at three European centres. Case definition was the culture of fungus or a positive PCR from the host cornea or anterior chamber after EK. A survey of the incidence of infection after EK was conducted by the European Eye Bank Association. The main outcome measure was the number of cases in which donor tissue had been stored in hypothermic medium compared with organ culture. RESULTS: The 10 cases occurred between 2014 and 2017. All donor corneas had been stored in hypothermic medium sourced from three US eye banks. Three pairs of mate corneas caused infections in six recipients. Candida spp were identified from nine cases, with one isolate of Purpureocillium lilacinum. Data on 16 862 corneas supplied for EK were available from 16 European eye banks for the 5-year period from 2012. There were 17 reported cases of infection, of which 15 (88%) were fungal infections and 14 (82%) were Candida spp. Fungal infection was reported from 3 of 14 476 (0.02%) corneas supplied in organ culture compared with 12 of 2386 (0.50%) corneas supplied in hypothermic medium (p<0.0001). The incidence of infection after hypothermic storage was similar for material sourced from Europe (0.52%) or the USA (0.61%). CONCLUSIONS: Infection after EK is strongly associated with Candida spp. The possible explanations for the higher incidence of infection when tissue is stored in hypothermic medium are discussed.