Prevalence and clinical consequences of cytomegalovirus DNA in the aqueous humour and corneal transplants

Aim To determine the prevalence and clinical consequences of cytomegalovirus (CMV) DNA in the aqueous and corneal tissues obtained at the time of corneal transplantation to evaluate the diagnostic value of PCR analysis in identifying patients at risk of postkeratoplasty CMV endotheliitis. Methods Thirty patients who underwent corneal transplantation were included in 2011. The aqueous, excised recipient corneas and donor corneoscleral rims were analysed by PCR for the presence of CMV DNA. The medical records of the patients were retrospectively reviewed and linked with PCR results. Results CMV DNA was detected in three (10%) aqueous, eight (26.7%) recipient corneas and six (20.0%) donor corneas obtained during keratoplasty from the 30 patients. Postoperatively, four patients, who had CMV DNA in either aqueous (3) or recipient cornea (1), were diagnosed with CMV endotheliitis based on clinical features and repeat aqueous tapping for real-time PCR analysis. At the median 60.5 months follow-up, 8 (72.7%), including 4 with postkeratoplasty CMV endotheliitis, of the 11 patients with CMV positivity in any one sample had graft failure, while 9 (47.3%) of the 19 patients without evidence of CMV DNA experienced graft failure. Conclusions We found a relatively high prevalence of CMV DNA in the aqueous and corneas obtained during keratoplasty. All the patients who had CMV positivity in aqueous developed CMV endotheliitis postoperatively and experienced graft failure eventually. Aqueous tapping at the time of corneal transplantation for PCR analysis may help to improve the diagnosis and follow-up management of postkeratoplasty CMV endotheliitis.