Destructive effects on endothelial cells of grafts in cytomegalovirus DNA-positive patients after keratoplasty

AIM: To investigate corneal graft survival rate and endothelial cell density (ECD) loss after keratoplasty in cytomegalovirus (CMV) positive patients.
METHODS: This was a retrospective cohort study. We analyzed the clinical data of patients who underwent viral DNA detection in aqueous humor/corneal tissue collected during keratoplasty from March 2015 to December 2018 at the Peking University Third Hospital, Beijing, China. To further evaluate the effect of CMV on graft survival rate and ECD loss, patients were divided into three groups: 1) CMV DNA positive (CMV+) group; 2) viral DNA negative (virus-) group, comprising virus- group eyes pairwise matched to eyes in the CMV+ group according to ocular comorbidities; 3) control group, comprising virus- group eyes without ocular comorbidities. The follow-up indicators including graft survival rate, ECD, ECD loss, and central corneal thickness (CCT), were analyzed by Tukey honestly significant difference (HSD) test.
RESULTS: Each group included 29 cases. The graft survival rate in CMV+ group were lowest among the three groups (P=0.000). No significant difference in donor graft ECD was found among three groups (P=0.54). ECD in the CMV+ group was lower than the virus- group at 12 (P=0.009), and 24mo (P=0.002) after keratoplasties. Furthermore, ECD loss was higher in the CMV+ group than in the virus- group in the middle stage (6-12mo) post-keratoplasty (P=0.017), and significantly higher in the early stage (0-6mo) in the virus- group than in the control group (P=0.000).
CONCLUSION: CMV reduces the graft survival rate and exerts persistent detrimental effects on the ECD after keratoplasty. The graft ECD loss associate with CMV infection mainly occurrs in the middle stage (6-12mo postoperatively), while ocular comorbidities mainly affects ECD in the early stage (0-6mo postoperatively).