Prevalence and Features of Keratitis with Quantitative Polymerase Chain Reaction Positive for Cytomegalovirus
Received 11 February 2009; received in revised form 12 June 2009; accepted 24 June 2009. published online 07 December 2009.
Purpose
To assess corneal scrapings and aqueous humor samples analyzed by polymerase chain reaction (PCR) that were positive for cytomegalovirus (CMV) in patients with keratitis of unknown origin and to investigate their clinical manifestations.
Design
Retrospective, interventional case series.
Participants
Seventy-eight patients with epithelial (n=37), stromal (n=12), or endothelial keratitis (n=29) of unknown origin examined at the Osaka University Medical Hospital.
Methods
Clinical examination and tears, corneal scrapings, and aqueous humor specimens were evaluated by real-time PCR for CMV.
Main Outcome Measures
Quantification of CMV DNA at the diagnosis of each type of keratitis with unknown origin and monitoring during the therapeutic course for CMV-positive cases.
Results
No cases of epithelial or stromal keratitis had CMV DNA. Seven of 29 corneal endotheliitis cases (24.1%) were positive for CMV. Cytomegalovirus-positive cases of corneal endotheliitis characterized by localized corneal edema and keratic precipitates included 4 patients who had undergone penetrating keratoplasty and were refractory to the treatment for graft rejection and 3 patients with idiopathic endotheliitis. Cytomegalovirus DNA copy numbers were estimated and ranged from 6.3×104 to 3.6×106/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. Five eyes (62.5%) had clinical improvement. In cases of endothelial keratitis, diabetes mellitus was significantly higher in patients positive for CMV (71.4%) than in patients negative for CMV (18.2%, P=0.016, chi-square test).
Conclusions
A total of 24.1% of cases with corneal edema of unknown origin were CMV positive and should be included in the differential diagnosis of idiopathic corneal endotheliitis or graft edema after penetrating keratoplasty, especially for bullous keratopathy. Real-time PCR for CMV, based on the diagnosis and monitoring of the clinical course, may be useful. Cytomegalovirus corneal endotheliitis requires early appropriate treatment using GCV. Because clinical remission after GCV may depend on the area of normal endothelium, early diagnosis and therapy are important for CMV corneal endotheliitis.
Financial Disclosure(s)
The authors have no proprietary or commercial interest in any materials discussed in this article.
Available online: December 6, 2009.
1Department of Ophthalmology, Osaka University Medical School, Suita, Japan
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