Abstract
Purpose: :
To determine the frequency of recurrences and adverse outcomes of keratitis due to Herpes Simplex virus (HSV) and the effect of prophylactic treatment with oral antiviral medication in a community-based setting over 32 years.
Methods: :
The database of the Rochester Epidemiology Project (REP) was used to identify all potential incident cases of HSV eye disease in Olmsted County, Minnesota between January 1, 1976 and December 31, 2007. Medical records were reviewed to identify initial episodes of HSV keratitis and/or uveitis, the medication history, recurrences and adverse outcomes. Initial episodes of HSV blepharitis or conjunctivitis were not considered incident cases. Recurrences were defined as blepharitis, conjunctivitis, keratitis and/or uveitis deemed by the examining clinician to be due to HSV. Adverse outcomes were defined as loss of vision to 20/200 or worse, corneal perforation or surgical intervention (i.e. trabeculectomy, keratoplasty, conjunctival flap) for HSV-related complications. The times to first recurrence and adverse outcome were estimated by using the Kaplan-Meier method. The association of prophylactic oral antiviral therapy with recurrence was investigated by using Cox proportional hazards models. Prophylaxis was used as a time-dependent covariate.
Results: :
A total of 340 cases were included. No cases of posterior segment disease were identified. The recurrence of ocular HSV following an initial episode of keratitis and/or uveitis was 31% at 1 year (95% C.I: 26-37%), 56% at 5 years (49-62%), 64% at 10 years (56-69%) and 73% at 20 years (64-79%). The risk of adverse outcomes was 7% at 5 years (95% C.I.: 6-10%), 9% at 10 years (5-13%), and 13% at 20 years (7-19%). Treatment with oral antiviral prophylaxis decreased the risk of first recurrence by a factor of 3.2 (95% C.I.: 1.2-8.8). The risk of adverse outcome did not decrease over time or during the last 8 years of the study period during which antiviral prophylaxis was more commonly used.
Conclusions: :
Recurrence after HSV keratitis or keratouveitis is common, even decades after the initial episode. In this community-based study, oral antiviral prophylaxis was associated with a 3-fold decrease in recurrence. However, prophylaxis was not associated with a decrease in adverse outcomes.
Keywords: herpes simplex virus • clinical (human) or epidemiologic studies: treatment/prevention assessment/controlled clinical trials • cornea: clinical science