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Magnetic systems for tarsorrhaphy
Anne Barmettler1, Nadee Nissanka, Mark I Rosenblatt
1*Department of Ophthalmology, Weill Cornell Medical College, New York, New York, U.S.A.; and †Department of Bioengineering, Cornell University, Ithaca, New York, U.S.A.
Purpose:
Paralytic lagophthalmos can cause exposure keratopathy. Current treatments have difficulties: extrusion, migration, allergic reaction, anatomical disruption, and technically difficult surgeries. The goal of this study was to design, create, and assess a new method for eyelid closure using magnets.
Methods:
This experimental study is approved by institutional review board. Creation of eyelid model and magnet systems: A model of the eyelid and eyeball was constructed to determine the necessary magnetic strength. Neodymium magnets were cast in silicone mold carriers. Assessment of temporary magnet systems in humans: 1) a magnet was affixed to the upper and lower eyelids, and 2) a magnet was affixed to the upper eyelid and another to eyeglasses. Parameters evaluated were eyelid positions and success of eyelid closure in healthy adult volunteers.
Results:
Magnetic force required to create the average eyelid opening force was calculated from the eyelid model to be equivalent to 4 magnets. The magnet system affixed to upper and lower eyelids resulted in complete eyelid closure in 5 of 5 normal controls, while the magnet system affixed to the upper eyelid and to spectacles resulted in complete eyelid closure in 10 of 13 normal controls.
Conclusions:
Magnetic systems for eyelid closure were designed that used either magnets affixed to both upper and lower eyelids or an upper eyelid magnetic component combined with a magnetic element in the lower rim of spectacles. Both were effective in eyelid closure in a model eye and normal controls. These systems may ultimately provide a simplified, safer, and less invasive method to treat paralytic lagophthalmos.