Uveitis cluster followed injections of bevacizumab at a Canadian retinal practice

NEW YORK — An outbreak of uveitis following bevacizumab injections caused an unusual cluster of cases in a Canadian retinal practice, a speaker said here at Retina Congress 2009.

Published studies have estimated an incidence of intraocular inflammation between 0.9% and 1.1% after Avastin (bevacizumab, Genentech/Roche) injection, but 23 cases were noted in 27 eyes during an outbreak in fall 2008, Michael Peter Fielden, MD, FRCS(C), said. Across Canada, 102 cases of uveitis were reported to health agencies.

Although all cases of uveitis occurred after injection with doses from the same lot number, several patients received doses from the same lot without incident, and one case in the cluster occurred unilaterally after a bilateral injection procedure, Dr. Fielden said.

Testing revealed a higher than usual amount of silicone oil in the lot, Dr. Fielden said.

There was a decrease in visual acuity in 22 of 27 eyes at time of presentation, but by the end of follow-up, only six eyes had lost vision from baseline.

"Of the six eyes with visual acuity loss, four returned to baseline at a visit prior to the final follow-up, suggesting that visual loss was from the underlying disease and not from any immediate damage," Dr. Fielden said.

Uveitis cases in the cluster were identified by patient presentation to the clinic, mostly occurring within 2 days. Typical symptoms included decreased vision, photophobia, and mild to moderate pain. Frequent clinical signs included redness, corneal injection, anterior chamber cellular reaction and viritis. All cases responded to steroid therapy, and there was no hypopia or endophthalmitis, Dr. Fielden said.