Clinical Trial Details
— Status: Completed
Administrative data
NCT number |
NCT03818204 |
Other study ID # |
18-166H |
Secondary ID |
|
Status |
Completed |
Phase |
N/A
|
First received |
|
Last updated |
|
Start date |
February 7, 2019 |
Est. completion date |
December 1, 2023 |
Study information
Verified date |
May 2024 |
Source |
Massachusetts Eye and Ear Infirmary |
Contact |
n/a |
Is FDA regulated |
No |
Health authority |
|
Study type |
Interventional
|
Clinical Trial Summary
Blepharoptosis (incomplete opening of the eyelids) occurs because of a disruption in the
normal agonist-antagonist neuro-muscular complex balance. An external device could restore
eyelid movement. 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 that could restore eyelid movement.
Description:
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. Tegadermâ„¢ (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.