An adjustable magnetic levator prosthesis for customizable eyelid reanimation in severe blepharoptosis: Design and proof-of-concept

Abstract

Purpose: Blepharoptosis is a common oculoplastic condition defined as incomplete opening of the upper eyelid. Although surgical approaches have become the mainstay for correction, they often fail to improve blink function. The purpose of this study was to develop an adjustable magnetic levator prosthesis (aMLP) as a non-surgical treatment option for severe ptosis, that allows blink reanimation. Methods: Magnetic force required to perform blink reanimation was characterized by evaluation of eye opening and closing using inter-palpebral fissure (IPF) outcomes with various combinations of eyelid array magnet and box magnets. The force that provided the optimal eye opening without limiting eye closing was selected for the development of the aMLP. The aMLP included an eyelid array magnet and an adjustable rotating spectacle magnet that allowed change in the magnetic direction, and hence change in the net magnetic interactive force between the spectacle and lid magnets. The clinical feasibility of the aMLP in improving eye opening without limiting eye closing was evaluated in ptosis patients through a proof-of-concept study using IPF and comfort outcomes. Results: Optimal eye opening and closing was achieved by a magnet-array combination providing 45gF in the tested ptosis population. Optimal size of spectacle magnet for aMLP was selected based on the simulations of rotating diametrically magnetized cylindrical magnets to achieve force ranges required for blink reanimation. The aMLP was able to modulate eye opening and closing with change in rotation (fitting) of the spectacle magnet in two ptotic patients. The best fitting of aMLP improved IPF opening without limiting eye closing (spontaneous or volitional blinking) with good comfort reported. Conclusions: Preliminary results suggest that the aMLP can correct ptosis without adversely affecting blink function. Further evaluation in a larger patient population is warranted. Translational Relevance: A non-surgical, proof-of-concept, adjustable magnetic treatment option for blink reanimation in patients with severe ptosis is presented.