Abstract
Purpose :
Case reports and animal studies have linked topical use of prostaglandin analogs to an increased risk of incident herpes simplex virus (HSV) and varicella-zoster virus (VZV) keratitis. We undertook a nested case-control study aimed at determining the risk of incident HSV/VZV keratitis in patients treated with topical glaucoma drops.
Methods :
The study was conducted using a random sample of 9 million patients registered in a health claims database (PharMetrics Plus, IQVIA, USA) in the United States between 2006 and 2016. We first created a cohort of new users of topical beta-blockers (BBs), prostaglandin agonists (PGAs), carbonic anhydrase inhibitors (CAIs) and alpha-2 agonists (A2As). Cohort members were followed to the first diagnosis of HSV/VZV defined by dispensation of the first prescription for an oral antiviral medication (acyclovir, valacyclovir, famciclovir) by an ophthalmologist or an optometrist. The date of this prescription was deemed the index date of the case. For each case, ten controls were selected from the database and matched to a case by follow up time, calendar time and age. Current use of a study drug (BBs, PGAs, A2As, CAIs) was defined as having an overlapping prescription with the index date in addition to having received a second prescription within 90 days of the first. Risk ratios (RRs) were computed comparing the risk of HSV/VZV among BB, PGA and A2A users compared to CAIs adjusting for gender and previous history of HSV.
Results :
6,154 cases and 61,540 controls were identified. The mean age for the cases and controls was 61.2 ± 11.9. Compared to CAIs, the adjusted RR for PGAs, A2As and BBs were 1.40 (95% CI 1.01-1.93), 1.87 (95% CI 1.14-3.07) and 1.34 (95% CI 0.93-1.93) respectively. Risk ratios did not change after adjusting for previous history of HSV.
Conclusions :
In a cohort of patients using glaucoma drops, prostaglandin agonists did not seem to confer additional risk of HSV/VZV compared to other anti-glaucoma drops.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.