A Magnetic Actuator Device for Fully Automated Blinking in Total Bidirectional Eyelid Paralysis: First Proof of Concept in a Human Participant.

PURPOSE

Currently, no solution exists to restore natural eyelid kinematics for patients with complete eyelid paralysis due to loss of function of both the levator palpebrae superioris and orbicularis oculi. These rare cases are prone to complications of chronic exposure keratopathy which may lead to corneal blindness. We hypothesized that magnetic force could be used to fully automate eyelid movement in these cases through the use of eyelid-attached magnets and a spectacle-mounted magnet driven by a programmable motor (motorized magnetic levator prosthesis [MMLP]).

METHODS

To test this hypothesis and establish proof of concept, we performed a finite element analysis (FEA) for a prototype MMLP to check the eyelid-opening force generated by the device and verified the results with experimental measurements in a volunteer with total bidirectional eyelid paralysis. The subject was then fitted with a prototype to check the performance of the device and its success.

RESULTS

With MMLP, eye opening was restored to near normal, and blinking was fully automated in close synchrony with the motor-driven polarity reversal, with full closure on the blink. The device was well tolerated, and the participant was pleased with the comfort and performance.

CONCLUSIONS

FEA simulation results conformed to the experimentally observed trend, further supporting the proof of concept and design parameters. This is the first viable approach in human patients with proof of concept for complete reanimation of a bidirectionally paretic eyelid. Further study is warranted to refine the prototype and determine the feasibility and safety of prolonged use.

TRANSLATIONAL RELEVANCE

This is first proof of concept for our device for total bidirectional eyelid paralysis.