title: Ibopamine challenge testing differentiates glaucoma suspect, stable glaucoma and progressive glaucoma cases.
abstract: BACKGROUND
  An ibopamine challenge is a novel technique for assessing glaucoma using ibopamine, a topical drug which temporarily increases aqueous production. We aimed to determine whether change in intraocular pressure (IOP) and/or optic cup volume (OCV) during the test differentiated between glaucoma patients at different stages of disease; namely, glaucoma suspects (GS), glaucoma patients who are stable (SG) and glaucoma patients who have demonstrated rapid progression (PG).
  
  
  METHODS
  Non-randomized clinical trial evaluating a diagnostic test.
  
  
  METHODS
  Sixty-one patients were recruited through glaucoma clinics at the Flinders Medical Centre (24 GS, 24 SG and 13 PG).
  
  
  METHODS
  Patients underwent IOP measurement and OCV assessment using optical coherence tomography. Two drops of ibopamine 2% solution were instilled into the study eye of each patient. After 45 min, IOP and OCV were reassessed. Changes from baseline were compared between groups.
  
  
  METHODS
  Change in IOP and OCV after ibopamine challenge.
  
  
  RESULTS
  Following the ibopamine challenge, IOP increased by 1.8 mmHg for GS patients, 4.5 mmHg for SG patients (P = 0.003) and 8.1 mmHg for PG patients (P < 0.0001). OCV increased by 0.2% for GS patients, 0.6% for SG patients and 5.5% for PG patients. This was not significantly different between GS patients and SG patients; however, it was significantly different between GS patients and PG patients (P < 0.0001), and between SG and PG patients (P = 0.001).
  
  
  CONCLUSIONS
  GS patients may be differentiated from those with SG or PG by their IOP response, and SG may be differentiated from PG patients by their change in OCV following an ibopamine challenge.
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; D003846:Deoxyepinephrine / Q000008:administration & dosage / Q000031:analogs & derivatives*; D018450:Disease Progression; D018491:Dopamine Agonists / Q000008:administration & dosage*; D005260:Female; D005901:Glaucoma / Q000175:diagnosis*; D006801:Humans; D007429:Intraocular Pressure / Q000187:drug effects*; D008297:Male; D008875:Middle Aged; D009798:Ocular Hypertension / Q000175:diagnosis*; D009883:Ophthalmic Solutions; D011680:Pupil / Q000187:drug effects; D041623:Tomography, Optical Coherence; D014065:Tonometry, Ocular; D014794:Visual Fields
chemical_list: D018491:Dopamine Agonists; D009883:Ophthalmic Solutions; C023487:ibopamine; D003846:Deoxyepinephrine
keywords: challenge test; glaucoma; ibopamine; progression; suspect