title: Nonpenetrating glaucoma surgery: a critical evaluation.
abstract: OBJECTIVE
  Nonpenetrating glaucoma surgery is popular in a number of countries because of its perceived superior safety profile to mitomycin-C trabeculectomy. This article critically evaluates recently published literature relating to nonpenetrating glaucoma surgery.
  
  
  RESULTS
  Recent modifications in nonpenetrating glaucoma surgery, including the use of implants, augmentation with antiproliferatives, and use of laser goniopuncture, appear to result in improved intraocular pressure control. Comparative studies suggest a better safety profile with nonpenetrating glaucoma surgery but higher long-term intraocular pressure than after trabeculectomy. Despite this perception, a difference in intraocular pressure control between mitomycin-C trabeculectomy and nonpenetrating glaucoma surgery, when the most recent modification has been incorporated, has not been demonstrated conclusively in randomized trials conducted over sufficiently long periods to be clinically important.
  
  
  CONCLUSIONS
  Nonpenetrating glaucoma surgery continues to evolve. Intraocular pressure-lowering efficacy seems to have improved with recent modifications in technique but the degree and longevity of intraocular pressure-lowering in comparison with trabeculectomy are still uncertain.
authors.affiliation: Glaucoma Service, Moorfields Eye Hospital, London, UK.
authors.forename: Usman
authors.initials: U
authors.lastname: Sarodia
authors.forename: Tarek
authors.initials: T
authors.lastname: Shaarawy
authors.forename: Keith
authors.initials: K
authors.lastname: Barton
mesh_terms: D049109:Cell Proliferation; D018463:Filtering Surgery / Q000379:methods*; D005901:Glaucoma / Q000473:pathology / Q000503:physiopathology / Q000601:surgery*; D020327:Glaucoma Drainage Implants; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology; D053685:Laser Therapy / Q000379:methods*; D014129:Trabecular Meshwork / Q000473:pathology; D016896:Treatment Outcome