Features of Keratitis With Quantitative Polymerase Chain Reaction Positive for Cytomegalovirus

Abstract

Purpose: : To investigate the relationship between cytomegalovirus (CMV) and keratitis with unknown origin by quantifying the amount of CMV using polymerase chain reaction (PCR) in their corneal samples and to report their manifestations.

Methods: : Forty-eight patients with epithelial keratitis, 16 patients with stromal keratitis, and 42 patients with endothelial keratitis were included in this study. Clinical examination and detection with realtime polymerase chain reaction (realtime PCR) for specific CMV-DNA against their tears, corneal scrapings, or aqueous humor were evaluated in each type of keratitis.

Results: : No cases of epithelial or stromal keratitis had no CMV-DNA. Fourteen of 42 corneal endotheliitis cases (33.3%) were positive for CMV. In these patients, other human herpes viruses such as herpes simplex virus type 1 were not detected. These cases were not complicated with systemic immunosuppressive disease and had no treatment with corticosteroid. Cytomegarovirus positive cases for corneal endotheliitis characterized by localized corneal edema and keratic precipitates included 8 patients who had undergone keratoplasty refractory to the treatment for graft rejection and 6 patients with idiopathic endotheliitis. CMV DNA copy numbers were ranged from 2.1×10⁴ to 8.1×10⁶/ml. In all positive cases, the numbers of CMV DNA copies decreased within weeks during treatment with systemic and topical ganciclovir (GCV) combined with a topical steroid. Ten eyes (71.4%) had clinical improvement after GCV therapy.

Conclusions: : Realtime PCR diagnosis detected CMV in endothelial keratitis, however, not in epithelial nor stromal keratitis with unknown origin. CMV should be included in the differential diagnosis of corneal endotheliitis with unknown origin.

Keywords: cytomegalovirus • inflammation • keratitis