title: A comparative study of trabeculectomy and the new clear-cornea filtering procedure, intrastromal diathermal keratostomy (IDK).
abstract: OBJECTIVE
  For the first time to compare the 1-year success rates of trabeculectomy and the new clear-cornea filtering procedure, intrastromal diathermal keratostomy (IDK).
  
  
  METHODS
  Prospective clinical observational study including 99 consecutively operated eyes (69 patients) with well-established primary open-angle glaucoma referred for filtering operation. We compared the change in intraocular pressure (IOP), number of anti-glaucomatous medication, complications and reoperations after 1 year. Seventy-four eyes were operated with trabeculectomy, and 25 with IDK. Complete success was defined as IOP ≤ 18 mmHg, IOP lowered ≥ 30%, no medication and no reoperation. Qualified success was defined as IOP ≤ 18 mmHg, and IOP lowered ≥ 30% with or without medication or reoperation.
  
  
  RESULTS
  Intraocular pressure pre- and postoperatively in the trabeculectomy group was 25.3 and 14.1 mmHg versus 23.8 and 15.8 mmHg in the IDK group. The number of medications pre- and postoperatively in the trabeculectomy group was 3.1 and 0.5 versus 3.2 and 1.3 in the IDK group. Forty-four (59%) of the eyes in the trabeculectomy group met the complete success criteria compared with 5 (20%) in the IDK group (p < 0.01). Sixty-eight (92%) in the trabeculectomy group and 16 (64%) in the IDK fulfilled the qualified success criteria (p < 0.01).
  
  
  CONCLUSIONS
  Both the complete and qualified 1-year success rates of IDK are significantly lower compared with the success rates of trabeculectomy. The IDK does not reduce the IOP as much as the procedure of trabeculectomy, and it carries a higher frequency of reoperations and more medication postoperatively. Thus, our prospective data do not support the procedure of IDK as 'the gold standard' for filtering surgery in patients with open-angle glaucoma.
authors.affiliation: Department of Ophthalmology, University Hospital of Copenhagen, Frederiksberg, Denmark. daniella@dadlnet.dk
authors.forename: Daniella
authors.initials: D
authors.lastname: Bach-Holm
authors.forename: Allan
authors.initials: A
authors.lastname: Storr-Paulsen
authors.forename: Jens Christian
authors.initials: JC
authors.lastname: Norregaard
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000477:Alkylating Agents / Q000008:administration & dosage; D000959:Antihypertensive Agents / Q000008:administration & dosage; D003315:Cornea / Q000601:surgery*; D005260:Female; D018463:Filtering Surgery / Q000379:methods*; D005902:Glaucoma, Open-Angle / Q000503:physiopathology / Q000601:surgery*; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology*; D008297:Male; D033401:Microscopy, Acoustic; D008875:Middle Aged; D016685:Mitomycin / Q000008:administration & dosage; D011183:Postoperative Complications; D011446:Prospective Studies; D012086:Reoperation; D014130:Trabeculectomy; D016896:Treatment Outcome; D014792:Visual Acuity / Q000502:physiology
chemical_list: D000477:Alkylating Agents; D000959:Antihypertensive Agents; D016685:Mitomycin