title: 2.5% and 10% phenylephrine for mydriasis in diabetic patients with darkly pigmented irides.
abstract: OBJECTIVE
  To compare the clinical efficacy and systemic side effects of2.5% and 10%phenylephrinefor mydriasis in diabetic patient with darkly pigmented irides.
  
  
  METHODS
  A prospective randomized double-blind controlled trial was conducted. One hundred diabetic patients were randomly allocated into 2.5% and 10% phenylephrine groups by block randomization. Pupil diameter, blood pressure and heart rate were measured before and after eye drop instillations.
  
  
  RESULTS
  The mean pupil diameters after instillation in the right eye were 7.05 +/- 0.71 mm (2.5% phenylephrine group) and 7.40 +/- 0.72 mm (10% phenylephrine group, p = 0.02) and in the left eye were 7.05 +/- 0.72 mm (2.5% phenylephrine group) and 7.39 +/- 0.72 mm (10% phenylephrine group, p = 0.02). There was no clinically significant difference in mean heart rate, mean systolic and diastolic blood pressure.
  
  
  CONCLUSIONS
  In diabetic patients with darkly pigmented irides, 10% phenylephrine is more effective than 2.5% phenylephrine with statistical significance. The authors recommend a single dose of 10% phenyleprine for mydriasis in these patients. However the lower concentration is recommended for use in those who exhibit a higher prevalence ofsignificant vascular disease and autonomic dysfunction and seem to be susceptible to severe adverse reaction of phenylephrine.
authors.affiliation: Department ofOphthalmology, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand.
authors.forename: Olan
authors.initials: O
authors.lastname: Suwan-Apichon
authors.forename: Tanapat
authors.initials: T
authors.lastname: Ratanapakorn
authors.forename: Ronakorn
authors.initials: R
authors.lastname: Panjaphongse
authors.forename: Suthasinee
authors.initials: S
authors.lastname: Sinawat
authors.forename: Thuss
authors.initials: T
authors.lastname: Sanguansak
authors.forename: Yosanan
authors.initials: Y
authors.lastname: Yospaiboon
mesh_terms: D000328:Adult; D000368:Aged; D015331:Cohort Studies; D003930:Diabetic Retinopathy / Q000150:complications / Q000188:drug therapy* / Q000473:pathology; D004311:Double-Blind Method; D005127:Eye Color; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015878:Mydriasis / Q000188:drug therapy* / Q000209:etiology / Q000473:pathology; D009184:Mydriatics / Q000008:administration & dosage*; D009883:Ophthalmic Solutions; D010656:Phenylephrine / Q000008:administration & dosage*; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D009184:Mydriatics; D009883:Ophthalmic Solutions; D010656:Phenylephrine