Cytomegalovirus-Positive Corneal Stromal Edema With Keratic Precipitates After Penetrating Keratoplasty: A Case-Control Study

Purpose: To identify differences between cytomegalovirus (CMV)-positive and CMV-negative eyes presenting as suspected endothelial graft rejection after penetrating keratoplasty (PK).Methods: A retrospective consecutive case-control series. Aqueous humor samples of all eyes with corneal stromal edema and keratic precipitates (KPs) after PK, seen at the Singapore National Eye Centre from 2007 to 2010, were analyzed for CMV DNA by polymerase chain reaction. Their charts were reviewed for demographic data, medical and ocular history, best-corrected visual acuity, intraocular pressure, anterior segment clinical findings, and therapy.Results: Of 11 eligible eyes (11 patients), 7 were CMV positive. All eyes were negative for herpes simplex virus and varicella zoster virus. The 2 groups were similar in age, gender, and previous ocular surgery. The main differences were the presence of extensive heavily pigmented KPs, Descemet membrane folds, and the absence of vascularization of the donor in CMV-positive eyes (100% vs. 0%, P = 0.003, Fisher exact test). All the CMV-positive eyes were treated with ganciclovir (5 systemic, 2 topical), and the control eyes received immunosuppression. However, all the grafts failed. Best-corrected visual acuity at the last visit was worse than 20/400 in all except 1 control eye, which had a follow-up of 30 months.Conclusions: There is a high prevalence of CMV infection in eyes that develop corneal stromal edema with KPs after PK. Heavy endothelial pigmentation, Descemet membrane folds, and the absence of donor vascularization may aid in the diagnosis of CMV in the event that aqueous analysis is not possible.