Three-Dimensional Printed Patient Specific Ptosis Crutches as a Nonsurgical Solution for Elevating Upper Eyelids in Myasthenia Gravis Patients1

Findlay, Megan; Heckmann, Jeannine M; Sivarasu, Sudesh

doi:10.1115/1.4033225

Cited by 5 publications

(4 citation statements)

References 8 publications

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“…Findlay et al . used a bottom‐up approach, influenced by patient specifications, which went through 87 iterations before the final design was realized . This design could be adjusted in the x‐, y‐ , and z ‐axes to cater to interindividual needs.…”

Section: Managing the Disability Of Op‐mgmentioning

confidence: 99%

A unique subphenotype of myasthenia gravis

Heckmann

Nel

2017

Annals of the New York Academy of Sciences

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While extraocular muscles (EOMs) are affected early in generalized myasthenia gravis (MG), and their treatment responsiveness is similar to nonocular muscles, we have identified an ophthalmoplegic (OP) subphenotype that remains resistant to treatment. This subphenotype of ophthalmoplegic MG (OP-MG) most commonly affects acetylcholine receptor antibody-positive cases with juvenile-onset MG and African genetic ancestry. However, a few OP-MG cases have been found with MuSK antibodies and triple-seronegative MG. In a proportion of OP-MG cases, the EOM treatment resistance manifests from treatment initiation, while in others the EOMs may initially respond until a critical trigger, such as treatment interruption or crisis. The management of OP-MG is an unmet need. Managing the visual disability may require a surgical or nonsurgical solution. The ideal case selection for surgery and the timing of surgery should be carefully considered. The pathogenesis of OP-MG remains unknown. A genetic study, using extended whole-exome sequencing and an "extreme" phenotype sample of OP-MG versus control MG cases differing only by their EOM responsivity to therapy, discovered several potentially functional OP-MG risk variants. These variants implicate myogenesis and gangliosphingolipid biosynthesis pathways at the EOM endplates in OP-MG.

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Section: Managing the Disability Of Op‐mgmentioning

confidence: 99%

A unique subphenotype of myasthenia gravis

Heckmann

Nel

2017

Annals of the New York Academy of Sciences

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“…These treatments usually involve a contact element by which the eyelid is pulled or pushed open. One of the first nonsurgical attempts to correct ptosis was described by Goldzieher in 1890, 9 and later by others, 10 – 15 is known as the “ptosis crutch.” This device uses a cushioned wire attached to the patient's spectacle to mechanically push the eyelid open. Another, more recent method is medical skin tape, used on the eyelid to pull the eyelid open.…”

Section: Introductionmentioning

confidence: 99%

An Adjustable Magnetic Levator Prosthesis for Customizable Eyelid Reanimation in Severe Blepharoptosis II: Randomized Evaluation of Angular Translation

Tirandazi,

Nadeau,

Woods

et al. 2023

Trans. Vis. Sci. Tech.

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Purpose Examine the effect of force modulation via angular translation of a static magnetic field for customizable treatment of severe blepharoptosis. Methods Prototype adjustable-force magnetic levator prostheses (aMLP) consisted of a spectacle-mounted magnet in rotatable housing and small eyelid-attached magnets embedded in a biocompatible polymer. Interpalpebral fissure (IPF) of 17 participants with severe blepharoptosis was continuously measured for one minute at five spectacle magnet angles, with order randomized and participant and data analyst masked. The hypothesis that angular position affected opening IPF (o-IPF), minimum blink IPF (m-IPF), and comfort ratings (1–10) was tested. Results The aMLP improved o-IPF from 4.5 mm without the device to 6.2 mm on the lowest force setting ( P < 0.001) and 7.1 mm on the highest setting ( P < 0.001) and allowed for complete volitional blink regardless of setting (average m-IPF 0.4 mm and no change with aMLP; P = 0.76). Spontaneous blink without the device (2.0 mm) was affected on the highest force setting (m-IPF 3.9 mm; P < 0.001) but only marginally so on the lowest setting (3.0 mm; P = 0.06). Comfort (7.6/10) did not vary with the angle ( P > 0.36). Profile analysis found substantial individual responses to angle ( P < 0.001), confirming the value of customization. Conclusions Angular translation provided adjustable force, which had a statistically and clinically meaningful impact on eye opening and the completeness of the spontaneous blink. This quantitative evidence supports continued use of the angular translation mechanism for force adjustment in the customizable magnetic correction of severe blepharoptosis. Translational Relevance Evidence for the benefit of customizable magnetic force via angular translation in a larger sample of participants than reported previously.

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“…We also have concerns that the crutch could cause injury with a fall or other blunt trauma or an abrasion during the necessary frequent adjustment, and at minimum is likely to be a constant mechanical irritant. It has recently been proposed to custom design and print crutches, 11 , 12 but customization does not address the main issues of eye closure and mechanical irritation. Traditional wire crutches are in fact customizable already by bending the wire.…”

Section: Introductionmentioning

confidence: 99%

Feasibility of Magnetic Levator Prosthesis Frame Customization Using Craniofacial Scans and 3-D Printing

Houston

Paschalis

2022

Trans. Vis. Sci. Tech.

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Purpose To determine the feasibility of a custom frame generation approach for nonsurgical management of severe blepharoptosis with the magnetic levator prosthesis (MLP). Methods Participants (n = 8) with severe blepharoptosis (obscuring the visual axis) in one or both eyes who had previously been using a non-custom MLP had a craniofacial scan with a smartphone app to generate a custom MLP frame. A magnetic adhesive was attached to the affected eyelid. The custom MLP frame held a cylindrical magnet near the eyebrow above the affected eyelid, suspending it in the magnetic field while still allowing blinking. The spectacle magnet could be rotated manually, providing adjustable force via angular translation of the magnetic field. Fitting success and comfort were recorded, and interpalpebral fissure (IPF) was measured from video frames after 20 minutes in-office and one-week at-home use. Preference was documented, custom versus non-custom. Results Overall, 88% of patients (7/8) were successfully fitted with a median 9/10 comfort (interquartile 7–10) and median ptosis improvement of 2.3 mm (1.3–5.0); P = 0.01). Exact binomial testing suggested, with 80% power, that the true population success rate was significantly greater than 45% ( P = 0.05). Five participants took the custom MLP home for one week, with only one case of mild conjunctival redness which resolved without treatment. Highest to lowest force modulation resulted in a marginally significant median IPF adjustment of 1.5 mm (0.8 to 2.7; P = 0.06). All preferred the custom frame. Conclusions The three-dimensional custom MLP frame generation approach using a smartphone app–based craniofacial scan is a feasible approach for clinical deployment of the MLP. Translational Relevance First demonstration of customized frame generation for the MLP.

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Three-Dimensional Printed Patient Specific Ptosis Crutches as a Nonsurgical Solution for Elevating Upper Eyelids in Myasthenia Gravis Patients1

Cited by 5 publications

References 8 publications

A unique subphenotype of myasthenia gravis

A unique subphenotype of myasthenia gravis

An Adjustable Magnetic Levator Prosthesis for Customizable Eyelid Reanimation in Severe Blepharoptosis II: Randomized Evaluation of Angular Translation

Feasibility of Magnetic Levator Prosthesis Frame Customization Using Craniofacial Scans and 3-D Printing

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