ABSTRACT
The drugs MMC and 5FU are the main anti-scarring agents in use at present, although we are still carrying out trials with single applications of beta-radiation, which has the advantage of good bleb morphology.48 Subconjunctival 5FU was the first established antimetabolite regimen based on the work of Parrish and his colleagues in Miami.49 Since then, the intraoperative regimens for MMC50 and 5FU, which we introduced on the basis of our cell culture results showing that long-term cellular growth arrest could be achieved with short applications of antimetabolites,10,11,51-53 are much more popular due to their convenience, supplemented by 5FU injections. However, a meta-analysis has suggested that fewer than four injections of 5FU may have little effect.54 Both treatments were generally associated with relatively small treatment areas combined with limbus-based surgery and a posterior incision resulting in the production of thin avascular blebs with complications including leakage, hypotony and endophthalmitis with long-term follow-up.4
Although methods have been described to treat these thin leaking blebs, including compression sutures and blood55 or Nd-YAG induced subconjunctival bleeding,56 these methods are totally satisfactory. Furthermore, the presence of an interpalpebral or inferiorly placed bleb is associated with a very high incidence of complications (up to 10 times normal) (Figure 22.6).
