Researchers used the American Academy of Ophthalmology's IRIS database to quantify the risk of endophthalmitis — inflammation of intraocular fluids — after injections with anti-VEGF drugs. They found that post-injection endophthalmitis occurs, on average, once every 3,500 injections.
A study taking advantage of the world’s largest patient specialty patient registry shows that post injection endophthalmitis (PIE) is a rare occurrence despite the growing number of patients being treated with injections of anti-vascular endothelial growth factor (VEGF) as a treatment of retinal conditions such as wet age-related macular degeneration and diabetic macular edema.
The research, presented Saturday at the American Society of Retina Specialists (ASRS) annual scientific meeting in Seattle, showed that smoking is a risk factor and that treating PIE with vitrectomy did not improve outcomes and may, in fact, worsen them.
Alia Durrani, M.D., of the Retina Institute of St. Louis, said the American Academy of Ophthalmology's Intelligent Research in Sight (IRIS) registry, with its data comprising 440 million patient visits and participation of approximately three-quarters of the practicing ophthalmologists in the United States, is well suited for investigating relatively rare events such as PIE.
Sifting through IRIS data from 2014 through 2020, Durrani and her colleagues 6,109 cases of PIE out of 20.1 million injections, which works out to an incidence of .0286%, or 1 in every 3,500 injections. Of the PIE cases, 738 eyes and 711 patients had bilateral injections, and there were 27 cases of bilateral PIE. The diagnosis was made, on average, four days after the injection. Speedy diagnosis appears to be important:Durrani reported that each day between initial injection of the anti-VEGF agent and diagnosis of endophthalmitis was associated with decreased visual acuity as measured on a Snellen test.
Bilateral, same-day injections did not increase the risk of PIE, Durrani reported, and the researchers did not find any significant association with region, race or insurance carrier. They did, though, find a slightly higher risk among current and past smokers.
However, the research findings may sow questions about the treatment of PIE, because compared with management with intravitreal injection of antibiotics alone, at one year eyes that treated vitrectomy had loss of visual acuity, Durrani said.