Injections of the cancer drug Avastin, which is also a treatment for the wet form of age-related macular degeneration, has been linked to reports of blindness.

Twelve patients in at least three separate clinics developed the serious bacterial infection Streptococcus endophthalmitis after undergoing injections of Avastin, which is administered in tiny doses to the eye, according to a Food and Drug Administration advisory issued Aug. 30. At least five of these patients have lost all remaining vision in the eyes that were treated with Avastin.

The infections have been traced back to a compounding pharmacy in Hollywood, FL, which repackaged intravitreal injections of Avastin from injectable 100-mg/4- mL, single-use vials into individual 1-mL single-use syringes. Officials say the repackaging process can open the door for bacterial contamination.

This is another blow to Avastin as an eye treatment. Recent studies have found Avastin to be as effective as its competitor Lucentis in treating macular degeneration in seniors, for a fraction of the price. Lucentis costs $2,000 per injection while Avastin costs just $50 per dose. Genentech manufactures both drugs.