[Management of non penetrating surgery failure]

Failure of deep sclerectomy with external trabeculectomy is defined as intraocular pressure (IOP) elevation in the post-operative period. This IOP increase is related to obstacles on the outflow pathway, which may be hindered either by internal obstacles (iris incarceration, internal trabecular layers insufficiently permeable to aqueous humor), or by external obstacles (excessive conjunctival scar such as fibrosis or cysts). These obstacles require specific treatment that is not always successful. Pre-, intra- and post-operative care that reduces the incidence of these complications is detailed.