title: Trabeculectomy for normal tension glaucoma: outcomes using the Moorfields Safer Surgery technique.
abstract: OBJECTIVE
  To evaluate long-term outcomes and complications of trabeculectomy for normal tension glaucoma (NTG) with contemporary surgical techniques.
  
  
  METHODS
  Retrospective consecutive, non-comparative case series of 131 eyes of 98 patients undergoing trabeculectomy between 2007 and 2013 in a dedicated NTG clinic. Data collected during routine clinical care were analysed. Assessment of clinical outcomes included intraocular pressure (IOP) reduction, bleb function, final visual acuity, evidence of glaucoma progression, postoperative complications and further surgical intervention. Surgical failure was defined as a failure to meet specified IOP-related criteria, the need to undergo further glaucoma surgery for raised IOP or loss of light perception vision. A further analysis was also performed which considered failure as glaucoma progression following surgery. Outcomes were evaluated using Kaplan-Meier life-table analysis.
  
  
  RESULTS
  The cumulative percentages of unqualified success as defined by a ≥30% reduction of IOP from baseline preoperative maximum (95% CI; IOP of all eyes: mean±SD) at 1, 2, 3 and 4 years after surgery were 91.1% (84.1% to 95.1%; 9.7±2.9 mm Hg), 74.1% (63.7% to 81.8%; 10.3±3.0 mm Hg), 64.8% (52.7% to 74.6%; 10.6±2.5 mm Hg) and 62.1% (49.3% to 72.6%; 10.2±2.1 mm Hg), respectively. At 2 years of follow-up there was no significant association between either previous cataract surgery or ethnicity and failure. Cumulative percentages of unqualified success at 4 years after surgery as defined by a filtering trabeculectomy bleb or absence of glaucoma progression were 91.6% (83.2% to 95.9%) and 92.3% (81.3% to 97.0%), respectively. Postoperative complications such as early (2.3%) and late (0.8%) hypotony were significantly lower than suggested by the current literature.
  
  
  CONCLUSIONS
  Trabeculectomy in NTG patients undertaken using contemporary surgical techniques and intensive postoperative management is associated with more successful long-term outcomes and fewer complications than the currently available literature suggests.
authors.affiliation: Glaucoma Service, Moorfields Eye Hospital, London, UK NIHR Biomedical Research Centre for Ophthalmology, UCL Institute of Ophthalmology & Moorfields Eye Hospital, London, UK Casey Eye Institute, Portland, Oregon, USA.
authors.forename: Hari
authors.initials: H
authors.lastname: Jayaram
authors.affiliation: Glaucoma Service, Moorfields Eye Hospital, London, UK NIHR Biomedical Research Centre for Ophthalmology, UCL Institute of Ophthalmology & Moorfields Eye Hospital, London, UK Singapore Eye Research Institute, Singapore, Singapore Discipline of Clinical Ophthalmology and Eye Health, University of Sydney, Sydney, New South Wales, Australia.
authors.forename: Nicholas G
authors.initials: NG
authors.lastname: Strouthidis
authors.affiliation: Glaucoma Service, Moorfields Eye Hospital, London, UK.
authors.forename: Deborah S
authors.initials: DS
authors.lastname: Kamal
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology*; D057066:Low Tension Glaucoma / Q000175:diagnosis / Q000503:physiopathology / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications; D012189:Retrospective Studies; D014065:Tonometry, Ocular; D014130:Trabeculectomy / Q000379:methods*; D016896:Treatment Outcome
keywords: Glaucoma; Treatment Surgery