title: Novel surgical procedures in glaucoma: advances in penetrating glaucoma surgery.
abstract: OBJECTIVE
  Despite late modifications and enhancements, traditional penetrating glaucoma surgery is not without complications and is reserved for patients in whom pharmacologic treatment and/or laser trabeculoplasty do not suffice to control the intraocular pressure. This article critically reviews recent advances in penetrating glaucoma surgery with particular attention paid to two novel surgical approaches: ab interno trabeculectomy with the Trabectome and implantation of the Ex-PRESS shunt.
  
  
  RESULTS
  Ab interno trabeculectomy (Trabectome) achieves a sustained 30% reduction in intraocular pressure by focally ablating and cauterizing the trabecular meshwork/inner wall of Schlemm's canal. It has a remarkable safety profile with respect to early hypotonous or infectious complications as it does not generate a bleb, but it can be associated with early postoperative intraocular pressure spikes that may necessitate additional glaucoma surgery. The Ex-PRESS shunt is more commonly implanted under a partial thickness scleral flap, and appears to have similar efficacy to standard trabeculectomy offering some advantages with respect to the rate of early complications related to hypotony.
  
  
  CONCLUSIONS
  Penetrating glaucoma surgery will continue to evolve. As prospective randomized clinical trials become available, we will determine the exact role of these surgical techniques in the glaucoma surgical armamentarium.
authors.affiliation: Glaucoma Consultation Service, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, Massachusetts 02048, USA.
authors.forename: Theodoros
authors.initials: T
authors.lastname: Filippopoulos
authors.forename: Douglas J
authors.initials: DJ
authors.lastname: Rhee
mesh_terms: D001082:Aqueous Humor / Q000378:metabolism; D018463:Filtering Surgery / Q000379:methods*; D005901:Glaucoma / Q000601:surgery*; D006801:Humans; D007429:Intraocular Pressure