title: Comparing brimonidine 0.2% to apraclonidine 1.0% in the prevention of intraocular pressure elevation and their pupillary effects following laser peripheral iridotomy.
abstract: OBJECTIVE
  To compare the effects of brimonidine 0.2% and apraclonidine 1% on intraocular pressure (IOP) and pupil size in patients undergoing laser peripheral iridotomy (LPI).
  
  
  METHODS
  Forty patients (40 eyes) with occludable angle or angle-closure glaucoma requiring LPI were recruited. Patients were randomized to receive either brimonidine 0.2% or apraclonidine 1% before and after LPI. The IOPs were measured at 1, 2 and 3 h after LPI, and pupil size was measured before and at 45 min after eyedrop instillation. Both parameters were analyzed using the t test.
  
  
  RESULTS
  There were 20 patients in each group. The baseline IOP was 17.1 +/- 3.2 mmHg for the brimonidine group and 16.7 +/- 2.8 mmHg for the apraclonidine group (P = 0.67) (t test). The mean IOP 3 h after laser treatment was 18.2 +/- 7.8 mmHg for the brimonidine group and 15.7 +/- 5.6 mmHg for the apraclonidine group (P = 0.25) (t test). There was no statistically significant difference between the two groups in the mean IOP changes at 1, 2, or 3 h after LPI. The mean change in pupil size after brimonidine was -0.33 +/- 0.37 mm and after apraclonidine was +0.90 +/- 0.87 mm. The difference was significant (P < 0.001).
  
  
  CONCLUSIONS
  Brimonidine 0.2% was found to have an efficacy comparable to that of apraclonidine 1.0% in preventing post LPI IOP spikes. Apraclonidine 1.0% tends to have a pupil dilating effect while brimonidine 0.2% tends to constrict the pupil.
authors.affiliation: Lo Ka Chow Ophthalmic Centre, Tung Wah Eastern Hospital, Hong Kong, People's Republic of China. nyuensy@netvigator.com
authors.forename: Nancy S Y
authors.initials: NS
authors.lastname: Yuen
authors.forename: Peggy
authors.initials: P
authors.lastname: Cheung
authors.forename: Sui Ping
authors.initials: SP
authors.lastname: Hui
mesh_terms: D000316:Adrenergic alpha-Agonists / Q000008:administration & dosage / Q000494:pharmacology*; D000368:Aged; D000068438:Brimonidine Tartrate; D003000:Clonidine / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000494:pharmacology*; D004311:Double-Blind Method; D005260:Female; D015812:Glaucoma, Angle-Closure / Q000601:surgery*; D006801:Humans; D007429:Intraocular Pressure / Q000187:drug effects*; D032801:Iridectomy; D053685:Laser Therapy; D008297:Male; D009798:Ocular Hypertension / Q000517:prevention & control; D009883:Ophthalmic Solutions / Q000008:administration & dosage / Q000494:pharmacology; D011183:Postoperative Complications / Q000517:prevention & control; D011446:Prospective Studies; D011680:Pupil / Q000187:drug effects*; D011810:Quinoxalines / Q000008:administration & dosage / Q000494:pharmacology*
chemical_list: D000316:Adrenergic alpha-Agonists; D009883:Ophthalmic Solutions; D011810:Quinoxalines; D000068438:Brimonidine Tartrate; C016986:apraclonidine; D003000:Clonidine