Clinical Trial to Improve the Magnetic Levator Prosthesis

NCT ID: NCT03818204

Last Updated: 2025-06-13

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: NA
• Total Enrollment: 19 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2019-02-07
• Study Completion Date: 2023-12-01

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.

Conditions

Blepharoptosis; Ptosis, Eyelid; Myasthenia Gravis; Stroke; Traumatic Brain Injury

Study Design

• Allocation Method: NON_RANDOMIZED
• Intervention Model: CROSSOVER
• Primary Study Purpose: TREATMENT
• Blinding Strategy: TRIPLE

Study Groups

Experimental Group baseline

Subjects with ptosis had their interpalpebral fissure measured continuously for 1 minute with no device.

Group Type: NO_INTERVENTION

No interventions assigned to this group

Experimental Group MLP 0 degree orientation

Subjects with ptosis had their interpalpebral fissure measured continuously for 1 minute with the MLP set at 0 degrees polarization angle.

Group Type: EXPERIMENTAL

Magnetic Levator Prosthesis (MLP)

Intervention Type: DEVICE

Neodymium magnet embedded in a glasses frame and a polymer embedded (PDMS) micro-magnet array fitted externally to the upper lid with IV 3000 securement film. The IV 3000 is FDA approved for extended wear on the skin. Tegaderm, which is essentially the same adhesive, is even FDA approved as an eye covering (we used Tegaderm in early studies but switched to IV 3000 for its superior ease of handling based on packaging technique).

Experimental Group MLP 30 Degree Orientation

Subjects with ptosis had their interpalpebral fissure measured continuously for 1 minute with the MLP set at 30 degrees polarization angle.

Group Type: EXPERIMENTAL

Magnetic Levator Prosthesis (MLP)

Intervention Type: DEVICE

Neodymium magnet embedded in a glasses frame and a polymer embedded (PDMS) micro-magnet array fitted externally to the upper lid with IV 3000 securement film. The IV 3000 is FDA approved for extended wear on the skin. Tegaderm, which is essentially the same adhesive, is even FDA approved as an eye covering (we used Tegaderm in early studies but switched to IV 3000 for its superior ease of handling based on packaging technique).

Experimental Group MLP 60 Degree Orientation

Subjects with ptosis had their interpalpebral fissure measured continuously for 1 minute with the MLP set at 60 degrees polarization angle.

Group Type: EXPERIMENTAL

Magnetic Levator Prosthesis (MLP)

Intervention Type: DEVICE

Neodymium magnet embedded in a glasses frame and a polymer embedded (PDMS) micro-magnet array fitted externally to the upper lid with IV 3000 securement film. The IV 3000 is FDA approved for extended wear on the skin. Tegaderm, which is essentially the same adhesive, is even FDA approved as an eye covering (we used Tegaderm in early studies but switched to IV 3000 for its superior ease of handling based on packaging technique).

Experimental Group MLP 90 Degree Orientation

Subjects with ptosis had their interpalpebral fissure measured continuously for 1 minute with the MLP set at 90 degrees polarization angle.

Group Type: EXPERIMENTAL

Magnetic Levator Prosthesis (MLP)

Intervention Type: DEVICE

Neodymium magnet embedded in a glasses frame and a polymer embedded (PDMS) micro-magnet array fitted externally to the upper lid with IV 3000 securement film. The IV 3000 is FDA approved for extended wear on the skin. Tegaderm, which is essentially the same adhesive, is even FDA approved as an eye covering (we used Tegaderm in early studies but switched to IV 3000 for its superior ease of handling based on packaging technique).

Experimental Group MLP 180 Degree Orientation

Subjects with ptosis had their interpalpebral fissure measured continuously for 1 minute with the MLP set at 180 degrees polarization angle.

Group Type: EXPERIMENTAL

Magnetic Levator Prosthesis (MLP)

Intervention Type: DEVICE

Neodymium magnet embedded in a glasses frame and a polymer embedded (PDMS) micro-magnet array fitted externally to the upper lid with IV 3000 securement film. The IV 3000 is FDA approved for extended wear on the skin. Tegaderm, which is essentially the same adhesive, is even FDA approved as an eye covering (we used Tegaderm in early studies but switched to IV 3000 for its superior ease of handling based on packaging technique).

Interventions

Magnetic Levator Prosthesis (MLP)

Neodymium magnet embedded in a glasses frame and a polymer embedded (PDMS) micro-magnet array fitted externally to the upper lid with IV 3000 securement film. The IV 3000 is FDA approved for extended wear on the skin. Tegaderm, which is essentially the same adhesive, is even FDA approved as an eye covering (we used Tegaderm in early studies but switched to IV 3000 for its superior ease of handling based on packaging technique).

Intervention Type: DEVICE

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.

• Minimum Eligible Age: 4 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

Massachusetts Eye and Ear Infirmary

OTHER

Sponsor Role: lead

Responsible Party

Kevin Houston

Assistant Professor of Ophthalmology

Responsibility Role: PRINCIPAL_INVESTIGATOR

Principal Investigators

Kevin Houston, OD, M. Sc.

Role: PRINCIPAL_INVESTIGATOR

UMass Chan Medical School

Locations

Schepens Eye Research Institute

Boston, Massachusetts, United States

Countries

United States

Provided Documents

Document Type: Study Protocol and Statistical Analysis Plan

View Document

Other Identifiers

18-166H

Identifier Type: -

Identifier Source: org_study_id