Clinical trial NCT03818204: Clinical Trial to Improve the Magnetic Levator Prosthesis
Official title: Clinical Trial to Improve the Magnetic Levator Prosthesis (MLP) Including the Development and Testing of a Novel Adjustable Force System
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Blepharoptosis
Ptosis, Eyelid
Myasthenia Gravis
Stroke
Traumatic Brain Injury
Lead sponsor: Massachusetts Eye and Ear Infirmary
Sponsor class: OTHER
First posted: 2019-01-28
Enrollment: 19
Sex: ALL
Minimum age (years): 4
Standard ages: CHILD
ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: NON_RANDOMIZED
Intervention model: CROSSOVER
Intervention model description: This is a prospective cross-over study with some aims having double-blind methodology. Randomization and masking will be used in aims 1 and 2 experiments. Aim 1: The spectacle magnet will be rotated to 1 of 4 settings in an order which will be counterbalanced using a Latin Square approach. Patient and experimenters will be masked to the actual force setting. Aim 2: 17 participants were randomized to be fitted first with either through thickness or through height polarization of the lid magnets using an online randomizer by a study staff not involved in the data collection or analysis who will keep the code. Every other subject in the sequence will be balanced to receive the alternative order. Counterbalancing is being used because of the small sample size.
Primary purpose: TREATMENT

Brief 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.

Detailed 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. 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.

Eligibility criteria: 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

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.

Primary outcomes:
measure: Change in Interpalpebral Fissure During Eye Opening
timeFrame: 6 minutes, 1 minute for each rotation position.
Secondary outcomes:
Other outcomes:
Locations:
city: Boston
country: United States
facility: Schepens Eye Research Institute
state: Massachusetts
Study officials:
affiliation: UMass Chan Medical School
name: Kevin Houston, OD, M. Sc.
role: PRINCIPAL_INVESTIGATOR
References: