title: Randomized clinical trial of the efficacy and safety of tropicamide and phenylephrine in preoperative mydriasis for phacoemulsification.
abstract: OBJECTIVE
  To compare the mydriatic effect and safety between different concentrations of tropicamide and phenyle-phrine in preoperative mydriasis for phaco-emulsification.
  
  
  METHODS
  Two hundred and seventeen consecutive eyes in the same number of Chinese patients undergoing phaco-emulsification under local or topical anaesthesia in a university-based eye hospital were analyzed. Patients were randomized into two groups by cluster randomization, each group receiving a different preoperative mydriatic regimen. Regimen A consisted of tropicamide 1.0% with phenylephrine 2.5%, and Regimen B consisted of tropicamide 0.5% with phenylephrine 0.5%. The main outcome measures were horizontal pupillary diameter, systolic, diastolic and pulse pressure and pulse rate.
  
  
  RESULTS
  The group who received Regimen A attained a mean horizontal pupillary diameter of 7.00 +/- 1.06 mm. Their pupils were significantly larger than those receiving Regimen B (6.61 +/- 1.03 mm, P = 0.007). No untoward cardiovascular effects were noted in either groups.
  
  
  CONCLUSIONS
  Regimen A attained better preoperative mydriasis for phacoemulsification than Regimen B. Both regimens were safe with regard to their cardiovascular effects. The combination of tropicamide 1.0% and phenylephrine 2.5% is recommended as preoperative mydriatic for phacoemulsification in Chinese patients who have darkly pigmented irides.
authors.affiliation: Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, People's Republic of China. lamth@ha.org.hk
authors.forename: Philip T H
authors.initials: PT
authors.lastname: Lam
authors.forename: Betty T M
authors.initials: BT
authors.lastname: Poon
authors.forename: Wai-Kwan
authors.initials: WK
authors.lastname: Wu
authors.forename: Stanley C C
authors.initials: SC
authors.lastname: Chi
authors.forename: Dennis S C
authors.initials: DS
authors.lastname: Lam
mesh_terms: D000368:Aged; D000772:Anesthesia, Local / Q000379:methods; D001794:Blood Pressure / Q000187:drug effects; D004359:Drug Therapy, Combination; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D007429:Intraocular Pressure / Q000187:drug effects; D008297:Male; D009184:Mydriatics / Q000008:administration & dosage / Q000627:therapeutic use*; D018918:Phacoemulsification; D010656:Phenylephrine / Q000008:administration & dosage / Q000627:therapeutic use*; D011300:Preoperative Care; D011446:Prospective Studies; D011680:Pupil / Q000187:drug effects*; D012449:Safety; D014331:Tropicamide / Q000008:administration & dosage / Q000627:therapeutic use*
chemical_list: D009184:Mydriatics; D010656:Phenylephrine; D014331:Tropicamide