番茄社区

BOSTON -- Reports of silicone oil droplets causing complications in patients after treatment with an anti-VEGF agent rose significantly in 2016, a researcher here found.

At one private retinal practice, incidence of silicone oil droplets -- which cause "floaters" in patients' vision -- after intravitreal bevacizumab (Avastin) injections that were preloaded in insulin syringes significantly increased from 0.03% during October 2015 to April 2016 to 1.73% during May to November 2016 (Fischer Exact Test, P<0.001), reported Rahul Khurana, MD, of Northern California Retina Vitreous Associates.

This increase corresponded with a issued by the American Society of Retina Specialists in August 2016, warning of an increase in reports of silicone oil droplets when using bevacizumab with these syringes.

Khurana commented on how prior research found that bevacizumab accounted for two-thirds of off-label injections, adding that one study found the other two anti-VEGF agents aflibercept (Eylea) and ranibizumab (Lucentis), were "not cost-effective relative to bevacizumab for the treatment of diabetic macular edema."

"It's all about the Benjamins," he said at a presentation at the . "The cost is what makes bevacizumab so attractive."

Khurana and colleagues examined 60 cases of intravitreal silicone droplets from 6,632 intravitreal bevacizumab injections done at their center. About 70% of patients were symptomatic, complaining of "floaters with spots of light," but around 90% reported improvement over time (range 2 months to 8 months), despite the silicone droplets being present on a fundoscopic exam. There was also no evidence of associated inflammation.

They found this complication was significantly more frequent when syringes were non-primed compared to primed (6.4% versus 0.5%, respectively, Fischer Exact Test P<0.001). Khurana speculated at the presentation that this was likely due to design, adding "without priming, more force is required to expel the oil." He offered a theory about the reason behind the increase in these complications, saying it may have been due to polydimethylsiloxane, a lubricant used to minimize friction within the syringe.

Khurana detailed the "frustrating" process involved in contacting the compounding pharmacy, who said it was "just a bad batch of syringes." He speculated that it might be "a manufacturing issue" for the insulin syringes, so his practice changed syringe types to those with a luer cone design, and those that do not use the polydimethylsiloxane lubricant.

"Physicians should counsel their patients about the risk of floaters with intravitreal bevacizumab preloaded with insulin syringes," argued the researchers.

But while Khurana thought that this manufacturing issue had the potential to impact multiple compounding pharmacies across the U.S., Frank Siringo, MD, an ophthalmologist at UCHealth in Aurora, said that his practice has not had this problem to date.

"As one of the most commonly used in-office drugs, compounded bevacizumab is very important," Siringo, who was not involved with the research, told 番茄社区 in an email. "This study highlights the myriad of quality control issues that can impact our patients when we use compounded pharmaceuticals."