Viral etiology of anterior uveitis in immunocompetent patients in North India

Abstract

Background: Uveitis is the leading cause of blindness worldwide. Among various forms, the anterior uveitis is most common. Herpes simplex virus (HSV) and varicella zoster virus (VZV) are known to cause anterior uveitis. However, recent studies have also reported the role of human cytomegalovirus (HCMV) in the causation of anterior uveitis in immunocompetent individuals. The present study aimed to study the prevalence of HSV-1, VZV and HCMV in patients presenting with anterior uveitis in a tertiary care hospital in North India. Methods & Materials: A total of 41 aqueous humor samples were obtained from the patients with anterior uveitis. The samples were subjected to DNA extraction followed by real time PCR using primers and probes targeting gD of HSV-1, ORF28 of VZV and IE gene of HCMV. Results: The mean age of the patients were 45.2 ± 13.03 years. The male:female ratio was 1.8:1. Redness, blurring of vision and pain was observed in 78% (32/41), 73.2% (30/41) and 46.3% (19/41) of the cases. The viral etiology was attributed in 30.2% (13/43) of patients. HSV-1, VZV and HCMV DNA were detected in 7(17%), 7 (17%) and 1 (2.5%) of patients respectively. The mean viral load for HSV-1 and VZV was found to 9.4X104 copies/μl and 1.6X105copies/μl respectively. The 3.2X104 copies/μl of load was found in HCMV positive patient. Viral uveitis patients presented with raised intraocular pressure (57%-60%), keratic precipitates (60%-71.4%) and iris atrophy (42.8%-60%). The majority of cases with viral uveitis had disease duration of ≤6 months (60%-71.4%). Conclusion: HSV-1 and VZV are the important causative agents of viral anterior uveitis. HCMV as an infectious cause for anterior uveitis is rare among immunocompetent patients in North India. Real time PCR is a sensitive and specific technique for the early diagnosis of viral uveitis which in turn will help in the early initiation of therapy thereby preventing irreversible loss of vision.