title: A double-blind study comparing 0.5% and 1% tropicamide for annual retinal screening in diabetic adolescents.
abstract: OBJECTIVE
  To determine whether there is any difference between 0.5% and 1% tropicamide in ocular discomfort and mydriatic efficacy in adolescents with Type 1 diabetes.
  
  
  METHODS
  In a double-blind study, one drop of 0.5% tropicamide was instilled in one eye and one drop of 1% instilled in the other eye of 30 subjects aged 12-18 years. Drop strengths were randomized. Pupil size was measured before instillation, at 10, 20 and 30 min. Discomfort was measured using a recognized pain scale.
  
  
  RESULTS
  Irrespective of the concentration of tropicamide used, all pupils dilated to at least 6 mm at 30 min, sufficient for successful ophthalmoscopy. Pain was significantly less when the lower concentration of tropicamide was used; pain score for the 0.5% group [median (interquartile range)] 1.0 (0-2) and 2.0 (1-3) for the 1.0% group, P = 0.009 (Wilcoxon rank test).
  
  
  CONCLUSIONS
  This minor change in practice significantly reduces the distress associated with drop instillation without compromising the clinical examination, and may thus be important in encouraging compliance at the yearly diabetic review.
authors.affiliation: Diabetes Centre, Children and Young Adults Team, The Ipswich Hospital NHS Trust, Heath Road, Ipswich, Suffolk IP4 5PD. UK.
authors.forename: J
authors.initials: J
authors.lastname: Hassler-Hurst
authors.forename: C
authors.initials: C
authors.lastname: Wadham
authors.forename: G
authors.initials: G
authors.lastname: Rayman
mesh_terms: D000293:Adolescent; D002648:Child; D003922:Diabetes Mellitus, Type 1; D003930:Diabetic Retinopathy / Q000175:diagnosis*; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008297:Male; D008403:Mass Screening / Q000379:methods; D009184:Mydriatics / Q000008:administration & dosage* / Q000009:adverse effects; D009887:Ophthalmoscopy / Q000379:methods; D010146:Pain / Q000139:chemically induced; D010147:Pain Measurement / Q000379:methods; D010349:Patient Compliance; D011680:Pupil / Q000187:drug effects; D014331:Tropicamide / Q000008:administration & dosage* / Q000009:adverse effects
chemical_list: D009184:Mydriatics; D014331:Tropicamide