Scarring of the filtering bleb is the main complication after glaucoma filtration surgery. Postoperative care most importantly determines success or failure of the operation. Both, preoperative antiinflammatory treatment and reduction or discontinuation of topical medication have a positive effect on postoperative conjunctival wound healing. After conventional postoperative care only about 40% of patients reach target pressures in the long-term without topical medication. Intensified postoperative care (IPC) increases the success rate by 25% after 5 years. Central to the concept of IPC is a wound modulating therapy which is adapted to the phases of wound healing of the filtering bleb. Evaluation of filtering bleb morphology is a prerequisite for the application of topical steroids and 5-fluorouracil. In addition, dedicated counseling of the patient and close follow-up are mandatory. In order to further increase the success rate of penetrating glaucoma surgery and decrease the side effects of the current antimetabolite therapy more research on wound healing as well as specific therapy to prevent scarring are necessary.