title: Validation of a new photogrammetric technique to monitor the treatment effect of Botulinum toxin in synkinesis.
abstract: OBJECTIVE
  To validate a new photogrammetric technique for quantifying eye surface area and using this to quantify the degree of improvement in symmetry in patients with oral-ocular synkinesis following Botulinum toxin injection.
  
  
  METHODS
  Feasibility study and retrospective outcomes analysis
  
  
  METHODS
  Ten patients' photographs were chosen from a photographic database. Their eye surface areas were measured independently by two raters using a graphics tablet. One rater repeated the procedure after 15 days. Bland-Altman plots were computed, ascertaining inter-rater and intra-rater variability. The eye surface areas of 19 patients were then derived from photographs taken before and after Botulinum toxin injections. Paired t-tests were used to analyse the significance of the difference in pre- and post-treatment symmetry.
  
  
  RESULTS
  Ninety per cent of eye surface areas derived from the two raters were within a coefficient of variation of 0.1 (95% CI: 0.05-0.15). Similarly, 90% of eye surface areas derived from one rater had a coefficient of variation of 0.08 (95% CI: 0.04-0.12). Botulinum toxin significantly reduced synkinesis resulting from lip puckering, Mona Lisa smiling and Hollywood smiling (P<0.05).
  
  
  CONCLUSIONS
  We have proposed a clinically valid tool for quantifying the effects of Botulinum toxin treatment for oral-ocular synkinesis. We recommend this method be used to monitor the response of such patients when receiving Botulinum toxin treatment.
authors.affiliation: Queen Victoria Hospital NHS Foundation Trust, East Grinstead, UK.
authors.forename: N T
authors.initials: NT
authors.lastname: Mabvuure
authors.forename: M-J
authors.initials: MJ
authors.lastname: Hallam
authors.forename: V
authors.initials: V
authors.lastname: Venables
authors.forename: C
authors.initials: C
authors.lastname: Nduka
mesh_terms: D018726:Anti-Dyskinesia Agents / Q000627:therapeutic use*; D001905:Botulinum Toxins / Q000627:therapeutic use*; D005158:Facial Paralysis / Q000150:complications; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D008297:Male; D015588:Observer Variation; D010781:Photography / Q000592:standards*; D015203:Reproducibility of Results; D012189:Retrospective Studies; D046608:Synkinesis / Q000188:drug therapy*
chemical_list: D018726:Anti-Dyskinesia Agents; D001905:Botulinum Toxins