Supportive role of aqueous humor analysis in the diagnosis and accurate management of Cytomegalovirus anterior uveitis: our experience

Abstract

Purpose :
The diagnosis of Cytomegalovirus (CMV) anterior uveitis in immunocompetent patients requires confirmation by polymerase chain reaction (PCR) analysis and/or intraocular antibody index (AI) assay. In this study, we analyzed the clinical features of CMV-positive eyes based on aqueous humor (AH) results, underlining the different contributions of PCR and AI in AH samples.

Methods : A retrospective chart review was conducted of HIV-negative patients attending the uveitis clinic at Arcispedale Santa Maria Nuova, Reggio Emilia, Italy with a diagnosis of hypertensive anterior granulomatous uveitis compatible with suspected CMV aetiology, from March 2015 to November 2017. The main outcome measures were: age, gender, ocular hypertension/glaucoma, presence of keratitis, endotheliitis, PCR, AI and mean diagnostic delay. AH and plasma samples were investigated by RT-PCR to determine the presence of viral DNA; total protein, albumin and IgG in aqueous humor and serum were analyzed by immunochemical nephelometry while specific antibody titers analysis was performed on ELISA assay in order to define AI index against CMV (AI cut-off=1.7). Real-time polymerase chain reaction (RT-PCR) was used to determine the number of plasma CMV DNA copies.

Results :
19 patients with suspected CMV uveitis (10 males, 9 females, mean age 46+/-16 yrs) were included in the analysis. In 16/19 (84%) humor samples, AI was positive, in the 3 samples negative for AI, PCR resulted positive. In all blood samples PCR resulted negative for CMV. Median diagnostic delay from onset of symptoms to aqueous tap was 34 months (IQR:10-108). Diagnostic delay was significantly associated to glaucoma (p=.004) and AI of humor samples (r=0.541, p=0.02). AI resulted significantly associated to glaucoma (r=0.47, p=.047). Endotheliitis showed a significant association with humor IgG levels.

Conclusions : Our data indicate that both lab tests are useful, in most cases complementary, to improve the diagnosis accuracy of anterior CMV uveitis. In some cases, when PCR alone fails to be diagnostic, AI remains the only procedure with a potentially significant impact on the management of these patients. An early diagnosis of CMV infection prevents the risk of developing glaucoma.

This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.