title: Comparison of pain scores with 30-gauge and 32-gauge needles for periocular botulinum toxin type a injections.
abstract: OBJECTIVE
  To determine whether a 32-gauge needle can reduce the pain associated with periocular injections of botulinum toxin type A compared with 30-gauge needles.
  
  
  METHODS
  In this prospective, randomized, masked study, 30 patients received bilateral periocular injections of botulinum toxin type A for benign essential blepharospasm. For each patient, a 30-gauge needle was used on one side of the face, and a 32-gauge needle was used on the other side. Equal number of injections and equal amounts of botulinum toxin type A at each injection site were administered on each side of the face. Patients were then asked to rate their pain level on each side of the face, using a standardized 11-point visual analogue pain scale.
  
  
  RESULTS
  The average pain score was 4.38 +/- 2.02 for 30-gauge needles and 3.98 +/- 1.65 for 32-gauge needles. Statistical analysis via Mann-Whitney U test confirmed the null hypothesis that no statistical difference in pain level existed between the 2 needle sizes.
  
  
  CONCLUSIONS
  There is no difference in perceived pain when comparing periocular botulinum toxin type A injections with 30- and 32-gauge needles. In addition, smaller gauge needles require special order and result in greater cost. The authors recommend continued use of 30-gauge needles for botulinum toxin injection in the office setting.
authors: Department of Ophthalmology, University of Minnesota, Minneapolis, Minnesota 55455, USA.
authors: David E
authors: DE
authors: Yomtoob
authors: Mohit A
authors: MA
authors: Dewan
authors: Michael S
authors: MS
authors: Lee
authors: Andrew R
authors: AR
authors: Harrison
mesh_terms: D000328:Adult; D000368:Aged; D001764:Blepharospasm / Q000188:drug therapy*; D019274:Botulinum Toxins, Type A / Q000008:administration & dosage*; D005260:Female; D006801:Humans; D007267:Injections; D008297:Male; D008875:Middle Aged; D009339:Needles / Q000009:adverse effects*; D009465:Neuromuscular Agents / Q000008:administration & dosage*; D010146:Pain / Q000175:diagnosis* / Q000209:etiology; D010147:Pain Measurement; D011446:Prospective Studies
chemical_list: D009465:Neuromuscular Agents; D019274:Botulinum Toxins, Type A