title: Ibopamine challenge testing becomes negative following successful trabeculectomy surgery.
abstract: BACKGROUND
  The ibopamine challenge test correlates well with a patient's peak diurnal intraocular pressure (IOP) measurement. We aimed to investigate the effect that a functioning trabeculectomy has on the ibopamine challenge test.
  
  
  METHODS
  Non-randomized prospective clinical trial evaluating a diagnostic test.
  
  
  METHODS
  Thirteen patients were recruited through glaucoma clinics at the Flinders Medical Centre. Of these, seven required surgical management with trabeculectomy surgery, whilst the remainder were managed medically.
  
  
  METHODS
  Patients underwent IOP measurement, and then two drops of Ibopamine 2% solution were instilled into the study eye of each patient. After 45 min, IOP was reassesed. A positive challenge test was considered to be a rise in IOP of greater than 3 mmHg. Changes from baseline were determined and compared between groups. Twelve months later, this test was then repeated in all patients.
  
  
  METHODS
  Change in IOP after ibopamine challenge.
  
  
  RESULTS
  Following the ibopamine challenge, IOP increased by 9.2 mmHg (SD 2.8) (100% positive) for medically managed patients and 7.2 mmHg (SD 2.0) (100% positive) for surgically managed patients (P = 0.18). The surgically managed group then underwent trabeculectomy surgery. Twelve months later, the ibopamine challenge was repeated. Following the repeat ibopamine challenge, IOP increased by 7.2 mmHg (SD 2.3) for medically managed patients and 0.3 mmHg (SD 1.3) for surgically managed patients (P < 0.0001). The medically managed group remained 100% positive, whilst the surgically manage group became 0% positive (Fisher Exact P = 0.044).
  
  
  CONCLUSIONS
  A glaucoma patient with a positive ibopamine challenge will show a negative challenge result when re-tested following trabeculectomy surgery.
authors.affiliation: Department of Ophthalmology, Flinders Medical Centre, Adelaide, South Australia, Australia.|Department of Ophthalmology, Flinders University, Adelaide, South Australia, Australia.
authors.forename: John
authors.initials: J
authors.lastname: Landers
authors.affiliation: Department of Ophthalmology, Flinders Medical Centre, Adelaide, South Australia, Australia.
authors.forename: Katja
authors.initials: K
authors.lastname: Ullrich
authors.affiliation: Department of Ophthalmology, Flinders Medical Centre, Adelaide, South Australia, Australia.|Department of Ophthalmology, Flinders University, Adelaide, South Australia, Australia.
authors.forename: Jamie E
authors.initials: JE
authors.lastname: Craig
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000959:Antihypertensive Agents / Q000008:administration & dosage; D003846:Deoxyepinephrine / Q000008:administration & dosage / Q000031:analogs & derivatives*; D018450:Disease Progression; D018491:Dopamine Agonists / Q000008:administration & dosage*; D005260:Female; D005901:Glaucoma / Q000175:diagnosis* / Q000503:physiopathology / Q000601:surgery*; D006801:Humans; D007429:Intraocular Pressure / Q000187:drug effects*; D008297:Male; D011446:Prospective Studies; D014065:Tonometry, Ocular; D014130:Trabeculectomy
chemical_list: D000959:Antihypertensive Agents; D018491:Dopamine Agonists; C023487:ibopamine; D003846:Deoxyepinephrine
keywords: challenge test; glaucoma; ibopamine; intraocular pressure; trabeculectomy