"Long-term, trabeculectomy has been proven to have a high success rate. It’s estimated that 90 percent were successful, with two-thirds of individuals no longer needing medication to control the condition afterward.
Approximately 10–12 percent of people who receive a trabeculectomy will require a repeat procedure. Research indicates that about 20 percent of trabeculectomy procedures don’t control IOP longer than 12 months, and 2 percent of procedures fail every year after that time frame. People who have the highest riskTrusted Source for this include those who have artificial lenses and those whose blebs become encapsulated."