Use of Dynamic, Automated Facial Analysis in Quantifying Oral-Ocular Synkinesis

Area of Science:

• Ophthalmology
• Neurology
• Biomedical Engineering

Background:

• Oral-ocular synkinesis frequently follows idiopathic facial paralysis (IFP).
• Objective, dynamic quantification of palpebral fissure changes in IFP is limited.
• Existing methods lack dynamic assessment of synkinesis-related eye movement abnormalities.

Purpose of the Study:

• To objectively measure palpebral fissure changes in IFP patients using automated facial tracking.
• To quantify dynamic, expression-specific oral-ocular coordination deficits.
• To establish a novel, objective method for assessing synkinesis severity.

Main Methods:

• A case-control study involving 12 controls and 30 IFP patients with synkinesis.
• Novel video-based facial tracking software assessed palpebral fissure dimensions.
• Measurements were taken at rest and during smile, laugh, and pucker expressions.

Main Results:

• Puckering demonstrated the most significant asymmetry (p < 0.001), with greater palpebral fissure reduction on the paralyzed side.
• No significant asymmetry was found during smile or laugh expressions.
• Dynamic modeling indicated puckering caused the fastest, largest decline in palpebral fissure symmetry (slope = -0.196, p < 0.001).

Conclusions:

• Dynamic facial tracking accurately quantifies expression-specific oral-ocular coordination disruptions in IFP.
• Puckering is a key indicator of synkinesis-related palpebral fissure asymmetry.
• This objective data can inform treatment strategies and patient counseling for IFP.