Clinical Trial to Improve the Magnetic Levator Prosthesis

Blepharoptosis (incomplete opening of the eyelids) occurs because of a disruption in the
normal agonist-antagonist neuro-muscular complex balance. An external device, if able to
generate an appropriately balanced force, could restore eyelid movement by performing the
paralyzed function; for example, a ptotic (droopy) eyelid could be opened, and the
functioning eyelid closure muscle could overcome the device's force (Conway, 1973; Barmettler
et. al, 2014; Houston et. al, 2014). Despite this seemingly straight-forward application,
permanent magnets for eyelid movement disorders have not thus far become an available
treatment. It is possible that earlier magnetic materials lacked the strength (at sizes which
were acceptable to patients) to effectively restore the blink, or methods of implantation or
external mounting were not effective. A newer class of permanent magnets made of alloys of
neodymium (Nd), iron (Fe) and boron (B) might provide the technology needed to develop a
feasible external magnetic device. They generate the strongest static magnetic fields yet
possible, (1.3T compared to 0.4T of conventional ferrite magnets) (Cyrot, 2005) with
exceptional uniaxial magnetocrystalline anisotropy, which makes them resistive to
demagnetization (Chikazumui, 1997). The increased magnetic force at a fraction of the size
has led to attempts for other medical applications including implantation for
gastroesophageal reflux disease (Ganz, 2013), in dental prosthetics (Uribe, 2006), ocular
reconstructive surgery (de Negreiros, 2012), and glaucoma (Paschalis et. al, 2013). Problems
with extended external non-surgical adhesion to the skin of the eyelid may be solved with
hydrocolloid-based medical adhesives e.g. Tegaderm™ (Chen, 1997), already used for IV
catheter securement, wound dressing, and as a protective eye covering (FDA, 1997). This
material is extremely thin, transparent, and oxygen permeable with an established safety
profile for days to weeks of wear. The hydrophyllic properties (FDA, 1997) may be beneficial
to the eyelids, which are often moist. In our prior work we established proof-of-concept data
demonstrating safety and efficacy for temporary management ptosis up to 2 hour per day for 2
weeks. Due to the sensitive force distance relationship characteristics of magnetic fields
and variable nature of ptosis (often worsens throughout the day) the MLP required frequent
readjustment and consistent correction was difficult to achieve. Other challenges included
lid redness with longer wear times (in the participants who wore the MLP longer than
instructed), incomplete spontaneous blinking, and difficultly with self-application of the
magnetic lid array to the eye lid. This study aims to address these challenges. In order to
improve the MLP we will determine the range of force in the target severe ptosis population
to open the lid and where blinking is inhibited, determine the best polarity combination
between the lid magnets and the spectacle magnet, determine if rotating the spectacle magnet
is a good method to allow simple force adjustment via a dial on the side of the frame,
determine if custom made frames improve stability of the frame, and create an applicator tool
to help participants apply the lid magnet themselves.

Inclusion Criteria:

- Experimental:

- Presence of ptosis for at least one eye which obscures the visual axis in the resting
position (without frontalis drive, lifting with forehead muscles)

- Moderate cognitive function or better defined as greater than or equal to 18 out of 30
on a pre-screening of the Mini-Mental State Exam

- Age 5 or older

- Control/Normal Vision Group:

- Absence of ptosis which obscures the visual axis

- Age 18 or older

Exclusion Criteria:

- Experimental:

- Absence of blepharoptosis or presence of a corneal ulcer.

- Those with a corneal ulcer are at risk for permanent loss of vision and should be
managed with proven methods.

- Age less than 5,

- Severe Cognitive impairment defined as MMSE score <18, behaviors consistent with
delirium (combinations of disorientation, hallucinations, delusions, and incoherent
speech), or lethargy. These individuals must be excluded since participation requires
competent self-care, reliable responses and cooperation during fitting of the devices.

- Control/Normal Vision Group:

- Presence of Blepharoptosis

- Age less than 18