In this lesson, you will learn about the approach to failed trabeculectomy. First, you will gain insight into glaucoma filtration surgeries, both penetrating and non-penetrating and the risk factors of trabeculectomy failure, and you will get acquainted with the definition of trabeculectomy success and failure. Next, you will learn about prevention, including Moorfields’ safer surgery, titratability using adjustable or releasable sutures, post-operative follow-up and assessment of blebs. Then, you will learn about complications, in particular, hypotony. Lastly, you will learn about management of bleb leaks, overfiltration hypotony, internal ostium obstruction, high IOP and resistance from flap.