By Emma Wells
Scheie Vision Summer 2018
A new analysis led by Brian VanderBeek, MD, MPH, MSCE, looked into the ocular safety profile of novel antithrombotics.
Oral antithrombotic medications are a mainstay for preventing blood clots, but they have associated ocular risks. Because of the anti-clotting nature of these medications, certain antithrombotics have been shown to increase risk for intraocular hemorrhages (bleeding in the eye).
Antithrombotics designed to reduce the blood’s clotting ability fall into two main categories: anticoagulants and antiplatelet drugs. Traditional anticoagulant therapies employ warfarin, which requires careful monitoring due to risk of excess bleeding. In recent years, several new antithrombotic medications that do not require routine monitoring have become increasingly popular. There are also several novel antiplatelet medications available, which are frequently prescribed instead of traditional antiplatelet therapies utilizing aspirin or clopidogrel.
While newer antithrombotics have been increasing in popularity, their ocular safety profile had not been extensively researched. “On top of that, there was a steady stream of case reports suggesting that the new ones were not as safe,” explained Dr. Brian VanderBeek, an Assistant Professor of Ophthalmology and retina specialist at the Scheie Eye Institute. “And there was no real data to back this idea up other than case reports.”
Recognizing this gap in the medical literature, Dr. VanderBeek set out to design a study assessing the risk of intraocular bleeding in patients taking novel antithrombotics. Dr. VanderBeek collaborated with Retinal Degeneration and Medical Retina Fellow Katherine Uyhazi, MD, PhD and UPenn clinical pharmacist and epidemiologist, Todd Miano, PharmD, MSCE. Together, they conducted a retrospective cohort study mining a large national insurance claims database. This analysis compared risk of intraocular hemorrhage from novel antithrombotics versus older medications over five years.
“We did two different comparisons, one for antiplatelets and one for anticoagulants,” said Dr. VanderBeek. The antiplatelet analysis compared the incidence of intraocular bleeding in patients taking clopidogrel (older drug) to patients taking prasugrel (novel drug). A similar analysis for anticoagulants compared warfarin to the novel anticoagulants dabigatran and rivaroxaban.
The study, published in JAMA Ophthalmology in February 2018, found that newer antiplatelet medications were no more likely to lead to intraocular hemorrhage than traditional ones. Additionally, newer anticoagulants actually had an improved ocular risk profile, reducing the risk of having an intraocular bleed by about 25%.
Dr. VanderBeek stressed that the study should not be taken as medical advice. “Talk to your primary care provider to decide what’s best for you,” he said.