Magnetic systems for tarsorrhaphy.
OBJECTIVE
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.
*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.
Anne
A
Barmettler
Nadee
N
Nissanka
Mark I
MI
Rosenblatt
Rohini
R
Rao
David
D
Lipson
Gary J
GJ
Lelli
D003316:Corneal Diseases / Q000517:prevention & control; D005141:Eyelid Diseases / Q000503:physiopathology / Q000628:therapy*; D005143:Eyelids / Q000503:physiopathology; D006801:Humans; D060328:Magnetic Phenomena; D059346:Magnets; D008954:Models, Biological; D009885:Ophthalmology / Q000295:instrumentation / Q000379:methods*