Glycoprotein B genotypes and clinical features in patients with recurrent cytomegalovirus anterior segment infection

BACKGROUND/AIMS: To investigate glycoprotein B (gB) genotypes of cytomegalovirus (CMV) in patients with recurrent anterior segment infections and evaluate their clinical characteristics. METHODS: This retrospective study included 11 patients with recurrent CMV anterior segment infection in whom CMV DNA was detectable by aqueous polymerase chain reaction (PCR) at both initial presentation and recurrence. The aqueous humour samples at initial presentation and recurrence were analysed for gB genotyping using a nested multiplex PCR protocol. Clinical features and outcomes were compared between patients with recurrence due to reactivation of initially predominant strains and those with emergence of additional strains. RESULTS: Initially, all 11 patients harboured CMV gB1 and/or gB3 genotypes-predominant strains-either alone or in combination with other minor strains. On recurrence, all patients showed reactivation of predominant strains; two exhibited identical strains, two retained predominant strains but lost some strains and seven acquired new strains in addition to predominant ones. Recurrence occurred following discontinuation or tapering of antiviral therapy, with over 90% of patients receiving corticosteroids concurrently. Most patients developed elevated intraocular pressure and corneal endothelial cell loss; one required trabeculectomy and five underwent corneal transplantation during follow-up. Patients with reactivation involving both predominant and new strains were significantly older (68.3 vs 56.3 years, p=0.04), with comparable clinical outcomes between groups. CONCLUSION: Recurrent CMV anterior segment infection primarily results from reactivation of predominant strains, underscoring the need for extended antiviral maintenance treatment. In elderly patients with late recurrences, reinfection with new strains should be considered.