Needle Revision with Antimetabolites in Bleb Failure

Glaucoma filtering surgery is unusual in that its goal is the creation and maintenance of a non healing fistula between two anatomic spaces that are normally not connected [1]. 

Fibroblasts, connective tissue elements, cytokines, aqueous humor and the surrounding vascular supply all influence what happens to a bleb over a long period of time.

The enemy of drainage procedure is excessive scarring [2]. 

Long-term studies showed a loss of intraocular pressure (IOP) control in a significant proportion of eyes with an initially successful trabeculectomy [2,3]. So follow up of glaucoma patients after surgery is mandatory as significant proportion develop bleb failure.