title: Brimonidine versus dapiprazole: Influence on pupil size at various illumination levels.
abstract: OBJECTIVE
  To evaluate the influence of dapiprazole versus brimonidine on pupil size at various illumination levels.
  
  
  METHODS
  Department of Ophthalmology, Johannes Gutenberg-University, Mainz, Germany.
  
  
  METHODS
  In randomized prospective study, 19 healthy volunteers received 2 ophthalmic solutions, dapiprazole and brimonidine, 1 in each eye, for intraindividual comparison. Before and after application, pupil diameter was measured using an infrared binocular pupillometer at 3 illumination levels (0.03, 0.82, and 6.4 lux).
  
  
  RESULTS
  Only slight pupil dilation was observed under scotopic conditions after application of both agents. After 20 minutes, the median reduction in pupil width was 1.4 mm for brimonidine and 0.9 mm for dapiprazole. These effects were statistically significant for both agents (both P < .001). The maximum effect was observed after 40 minutes and remained stable through the next measurement at 180 minutes. Under mesopic lighting conditions, only a slight effect (<1 mm) was seen.
  
  
  CONCLUSIONS
  Pupil mydriasis at scotopic illumination levels was reduced by both drugs in a similar fashion. Because of the slightly stronger effect of brimonidine, application of this agent 20 minutes before activities in dimly lit areas or at night may be recommended for photic phenomena following refractive surgery.
authors.affiliation: Department of Ophthalmology, Johannes Gutenberg-University, Mainz, Germany. Susanne.marx-gross@uni-mainz.de
authors.forename: Susanne
authors.initials: S
authors.lastname: Marx-Gross
authors.forename: Frank
authors.initials: F
authors.lastname: Krummenauer
authors.forename: H Burkhard
authors.initials: HB
authors.lastname: Dick
authors.forename: Norbert
authors.initials: N
authors.lastname: Pfeiffer
mesh_terms: D000316:Adrenergic alpha-Agonists / Q000008:administration & dosage / Q000494:pharmacology*; D000317:Adrenergic alpha-Antagonists / Q000008:administration & dosage / Q000494:pharmacology*; D000068438:Brimonidine Tartrate; D003623:Dark Adaptation; D003941:Diagnostic Techniques, Ophthalmological; D006801:Humans; D008027:Light; D009883:Ophthalmic Solutions / Q000008:administration & dosage / Q000494:pharmacology; D010879:Piperazines; D011446:Prospective Studies; D011680:Pupil / Q000187:drug effects*; D011810:Quinoxalines / Q000008:administration & dosage / Q000494:pharmacology*; D014230:Triazoles / Q000008:administration & dosage / Q000494:pharmacology*
chemical_list: D000316:Adrenergic alpha-Agonists; D000317:Adrenergic alpha-Antagonists; D009883:Ophthalmic Solutions; D010879:Piperazines; D011810:Quinoxalines; D014230:Triazoles; D000068438:Brimonidine Tartrate; C035289:dapiprazole