Quantitative Measurement of Evolution of Postparetic Ocular Synkinesis Treated with Botulinum Toxin Type A

Abstract

The Sunnybrook Facial Grading System is considered one of the best scales available to grade facial motility and postparetic synkinesis. To measure facial landmarks and movement excursion, a new software, the Facial Assessment by Computer Evaluation, has been proposed. The aim of this study was to quantify eye synkinesis improvement after botulinum toxin type A injections using the new software and to compare this method with the Sunnybrook grading system. The study included 40 injection sessions on 29 Caucasian outpatients with facial synkinesis. Before and 2 weeks after the injection, patients were evaluated using the Italian version of the Sunnybrook system. Eyelid fissure size at rest, during lip puckering, and while smiling was measured with the new software. After botulinum infiltration, the Sunnybrook grading system showed a global facial improvement with reduction of synkinesis and increase of static and dynamic symmetry. The Facial Assessment software detected an increase of ocular fissure measure at rest, during lip puckering, and especially during smiling, and the improvement was positively correlated with initial asymmetry. A single point of the Sunnybrook system synkinesis score corresponded to a mean difference of 0.77 mm during smiling and 1.0 mm during lip puckering. The Facial Assessment by Computer Evaluation measure allowed the authors to quantify the improvement of eye synkinesis after botulinum toxin type A injection. The Sunnybrook Facial Grading System provided an immediate instrument with which to monitor treatment in routine clinical practice, whereas the Facial Assessment system gave a more accurate quantitative assessment. Diagnostic, II.