Eyeworld

41 EW GLAUCOMA November 2018 According to the European Glaucoma Society, indications/pro- tocol for MMC are tailored to the se- verity of glaucoma: for medium risk glaucoma, give 5-FU or MMC and for high-risk glaucoma, give MMC, using the conventional soaked sponge method or by sub-Tenon's injection. Antifibrotic complications include corneal ulceration, scleral necrosis, conjunctival perforation, thin-walled and ischemic blebs, and chronic hypotony. Anti-VEGF agents are indicated as they have a direct effect on vascular prolif- eration and an indirect effect of reducing the influx cytokines into the bleb. But there is no consensus about their efficacy especially in refractory glaucoma. "Anti-inflammatory agents are crucial after surgery. A long course of corticosteroids and NSAIDs should be planned according to the bleb status. Corticosteroid injections with dexamethasone have been shown to reduce fibrosis and im- prove bleb status. In vitro diclofenac and phenidone have been shown to reduce fibrosis proliferation and cell attachment. New adjuvants capable of specifically modulating conjunc- tival wound healing without the associated side effects are under study," she said. Early fibrosis is treated with pressure and laser suture lysis. In late-stage fibrosis, needling is a safe and effective method to save a failed or failing filtering bleb. The princi- ple is to disrupt subconjunctival scar tissue, usually followed by the injec- tion of 5-FU or MMC. Blebs that are needled within the first 3 months of filtration surgery have a better prognosis than after 3 months, after which trabeculectomies all have the same prognosis. While there is no real consensus, Dr. Ouertani thinks that multiple needlings and high IOP immediately after needling have poor prognoses. Several failed needlings are an indication for a new surgery. EW Editors' note: Dr. Ouertani has no financial interests related to her comments. Contact information: Ouertani: amel.ouertani@hotmail.com treatment, and the avoidance of bleb procedures in young patients. Infec- tions are treated with antibiotics and corneal patching when involving necrotizing blebitis. Filtering bleb complications: Hypertony A hypertonic filtering bleb can result from tight sutures, internal obstruc- tion, or conjunctival fibrosis. "If the closure is too tight, you can prevent it by using adjustable sutures and treat with argon laser suture lysis," Dr. Ouertani said. "Obstruction of the filtering site can be caused by the iris, vitreous, ciliary body, lens, or from blood. Prevention is a large base iridectomy and treatment is with argon laser for pigment- ed sutures and Nd:YAG laser for non-pigmented sutures. The main complication of filtering surgery is conjunctival fibrosis. Success of the surgery depends on the incomplete scarring of the surgical wound." Fibroblastic proliferation begins on the fifth or sixth day after surgery and continues for around 1 year. A vascularized and thick-walled bleb is likely to be fibrotic. A fibrotic bleb is shallow and sometimes encapsu- lated. Preventing bleb fibrosis at the preoperative stage includes treat- ment of the ocular surface and ad- nexa with anti-inflammatory med- ication and cessation of preserved anti-glaucoma drops 1 month before surgery. Perioperatively, Dr. Ouertani advised the careful choice of the tra- beculectomy site, the avoidance of scars, and the protection of the con- junctival flap. "We have to be gentle with hemostasis because vascular aggression will cause fibrin clots and platelet activation, which activate inflammatory mediators, like VEGF, cytokines, and interleukins, causing a severe fibrotic reaction," she said. Fibrosis "Evidence suggests that intraoper- ative MMC is more effective than postoperatively administered 5-FU, particularly in patients at high risk of surgical failure," Dr. Ouertani said. "Other evidence showed no difference in primary trabeculec- tomy eyes that were followed long term when both agents were used intraoperatively. Overall, MMC is considered to be more effective at long-term reduction in IOP and in cases of refractory glaucoma."

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