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Eyelid movements in facial paralysis
P A Sibony1, C Evinger, K A Manning
1Department of Ophthalmology, SUNY, Stony Brook 11794.
Archives of Ophthalmology (Chicago, Ill. : 1960)
|November 1, 1991
Summary
Facial paralysis significantly impairs eyelid closure, slowing blink velocity and reducing orbicularis oculi contraction. Eyelid saccades also show decreased amplitude and velocity in affected individuals.
Area of Science:
- Ophthalmology
- Neurology
- Biomechanics
Background:
- Facial paralysis affects eyelid function, impacting orbicularis oculi muscle activity.
- Understanding blink dynamics is crucial for managing eyelid abnormalities.
Purpose of the Study:
- To investigate eyelid movement abnormalities in patients with unilateral facial paralysis.
- To analyze the kinematic characteristics of blinks and lid saccades in affected individuals.
Main Methods:
- Utilized the magnetic search coil technique to record eyelid movements.
- Studied six patients with unilateral, isolated facial paralysis.
Main Results:
- Observed reduced orbicularis oculi contraction and slowed blink closing velocity.
- Blink closing velocity deviated from the normal linear relationship with amplitude (main sequence).
- Lid saccades exhibited decreased amplitude and velocity, though peak velocities remained on the main sequence.
Conclusions:
- Unilateral facial paralysis leads to distinct alterations in blink dynamics and lid saccade kinematics.
- The study provides insights into the passive mechanisms underlying downward lid saccades.