Multiplexing Prism for Monocular Vision

Overseen By Eli Peli, OD

Age: Any Age

Sex: Any

Trial Phase: Academic

Sponsor: Massachusetts Eye and Ear Infirmary

Disqualifiers: Cognitive dysfunction, Balance problems, Others

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Compensation: Varies

Number of Visits: 3

Duration: 4 months

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial tests a new device called a multiplexing prism designed to assist people who have lost vision in one eye. The device aims to widen their field of view, enhancing their ability to notice someone approaching during a simulated walking task. Participants will perform the task with and without the prism to determine its effectiveness. Ideal candidates for this trial have lived with vision loss in one eye for over a year and maintain good vision in their remaining eye. As an unphased trial, this study offers participants the chance to contribute to innovative research that could improve daily life for those with similar vision challenges.

Do I have to stop taking my current medications for the trial?

The trial protocol does not specify whether you need to stop taking your current medications.

What prior data suggests that the multiplexing prism is safe for individuals with acquired monocular vision?

Research shows that the multiplexing prism is designed to help individuals with vision in only one eye by widening their field of vision. However, the research does not clearly indicate the prism's safety. Specific information about side effects or user comfort is lacking.

The trial is in a phase labeled "Not Applicable," which suggests the study focuses more on the device's effectiveness than on safety. Testing a device at this stage often implies no major safety issues have emerged.

Participants in the trial will use the prism during a simulated walking task to determine if it helps them notice people approaching. Although specific safety data is unavailable, the trial's emphasis on effectiveness might reassure potential participants. ^{1 2 3 4 5}

Why are researchers excited about this trial?

The multiplexing prism is unique because it offers a non-invasive approach to improving monocular vision, which is vision in just one eye. Unlike traditional methods that focus on corrective lenses or surgery, this prism uses an innovative optical design to help people detect moving objects, like pedestrians, that may collide with them. Researchers are excited because this approach could enhance spatial awareness and safety for individuals with monocular vision, offering a practical and immediate solution without the need for invasive procedures.

What evidence suggests that the multiplexing prism is effective for expanding the field of view in individuals with monocular vision?

Research shows that the multiplexing prism (MxP) can greatly improve vision for individuals who have lost sight in one eye. Studies have found that the MxP widens the field of view by about 25 degrees. As a result, users can see more of their surroundings, making it easier to notice pedestrians and other objects. In this trial, participants will perform tasks with and without the MxP to assess its effectiveness. Specifically, participants using the MxP reported better performance in tasks involving spotting moving objects. This suggests that the prism could be a helpful tool for enhancing spatial awareness. ^{1 2 3 4 6}

Who Is on the Research Team?

Eli Peli, OD

Principal Investigator

Schepens Eye Research Institute

Are You a Good Fit for This Trial?

This trial is for individuals who have lost vision in one eye (with no light perception) for over a year, but have good corrected visual acuity better than 20/32 and no field defects in their seeing eye. They should not have health issues like seizures or motor movement problems.

Inclusion Criteria

I have been blind in one eye for more than a year.

I do not have seizures or problems with motor movements.

My corrected vision in my seeing eye is better than 20/32.

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Treatment

Participants perform a simulated walking task with and without the multiplexing prism to test its efficacy in improving detection of colliding pedestrians

4 months

Approximately 3 sessions, up to 3 hours each

Follow-up

Participants are monitored for safety and effectiveness after treatment

4 weeks

What Are the Treatments Tested in This Trial?

Interventions

• Multiplexing Prism

Trial Overview

The study is testing a device called multiplexing prism designed to widen the field of view for people with monocular vision. Its effectiveness will be evaluated through a simulated walking task to see if it helps detect pedestrians that could collide with them.

How Is the Trial Designed?

Group I: Detection of colliding pedestrian Experimental Treatment 1 Intervention

Participants will perform a simulated walking task in which surrounding pedestrians will walk towards and make a collision. Participants will respond by pressing buttons to indicate the direction of the colliding pedestrians. Participants will perform the task with and without the multiplexing prism in random orders.

Who Is Running the Clinical Trial?

Massachusetts Eye and Ear Infirmary

Lead Sponsor

Trials

115

Recruited

15,000+

National Eye Institute (NEI)

Collaborator

Trials

572

Recruited

1,320,000+

Published Research Related to This Trial

The Welch Allyn SureSight autorefractor demonstrated high validity and repeatability in measuring peripheral refractive error, showing measurements closely aligned with the Grand Seiko WR-5100K, with no significant differences across various gaze angles.

In contrast, the Plusoptix PowerRefractor showed more myopic measurements and significant differences from the Grand Seiko in several gaze directions, indicating it may be less reliable for peripheral refractive assessments.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Repeatability and Validity of Peripheral Refraction with Two Different Autorefractors. Morrison, AM., Mutti, DO.[2021]

In a study of 100 preschool children, the MTI photoscreener demonstrated higher data acquisition success (96%) compared to the Welch-Allyn SureSight autorefractor (76%), indicating better usability in a clinical setting.

While the SureSight showed comparable sensitivity to the MTI for detecting amblyogenic factors, its low specificity led to a high rate of over-referrals, suggesting that the MTI may be a more reliable option for accurate vision screening in young children.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Comparison of the MTI Photoscreener and the Welch-Allyn SureSight autorefractor in a tertiary care center. Rogers, DL., Neely, DE., Chapman, JB., et al.[2016]

In a study of 3170 children aged 6 months to 12 years, the Plusoptix Autorefractor A09 (POA09) detected refractive errors with varying reliability, identifying astigmatism and anisometropia more effectively than hyperopia and myopia.

The study found that while the POA09 had a detection rate of 60% for astigmatism and 53.3% for anisometropia, its overall reliability was limited without cycloplegia, suggesting that systematic amblyopia screening should include cycloplegic assessments for better accuracy.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

[Detections of refractive risk factors for amblyopia with Plusoptix Autorefractor A09]. Al-Romhein, P., Fröhlich, M., Schmickler, S., et al.[2022]

The base-in multiplexing prism (MxP) glasses significantly improved the ability of patients with acquired monocular vision (AMV) to detect pedestrians approaching from their blind side, providing a true field expansion of about 25°.

In a virtual reality walking environment, participants with simulated AMV showed better pedestrian detection rates when using the MxP, indicating that these glasses could help reduce collision risks for individuals with AMV.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Field Expansion with Multiplexing Prism Glasses Improves Pedestrian Detection for Acquired Monocular Vision. Jung, JH., Castle, R., Kurukuti, NM., et al.[2023]

The plusoptiX A12 device demonstrated high accuracy in detecting amblyogenic risk factors in children, with strong correlations in measurements of myopia and astigmatism, making it a reliable screening tool.

While the device showed excellent sensitivity and specificity for myopia (86% and 93%, respectively) and astigmatism (85% and 98%), its reliability was lower for hyperopia, indicating a potential underestimation of hyperopic refractive errors.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

A comparison of plusoptiX A12 measurements with cycloplegic refraction. Fogel-Levin, M., Doron, R., Wygnanski-Jaffe, T., et al.[2022]

The Biessels binocular prism loupe spectacles, developed in 1970, offer variable magnification up to 12 times and provide comfortable stereoscopic vision, making them superior to previous low vision aids like Galilean telescopic spectacles.

Over the past 7 years, more than 500 of these loupes have been successfully delivered to low vision patients, including 40 for microsurgery, demonstrating their efficacy and positive impact on users' visual capabilities.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

[The prism loupe spectacles used as low vision aid and in microsurgery (author's transl)]. Oosterhuis, JA., Biessels, WJ.[2009]

In a study of 94 patients with diplopia, 88% experienced complete or partial resolution of their double vision after being prescribed prisms, indicating high efficacy of this treatment method.

The most significant improvements were seen in patients with divergence insufficiency and skew deviation (100% resolution), while those with convergence insufficiency had a lower improvement rate of 64%.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Effectiveness of prisms in the management of diplopia in patients due to diverse etiologies. Tamhankar, MA., Ying, GS., Volpe, NJ.[2012]

In a study involving patients with age-related macular degeneration (AMD), the use of yoke prisms significantly improved best corrected visual acuity (BCVA) levels, indicating their efficacy in enhancing vision by redirecting images to preferred retinal loci (PRLs).

The distance BCVA achieved with prisms was nearly the same as the potential visual acuity (PVA), suggesting that prisms can effectively restore visual function in low vision cases.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Restitution of potential visual acuity in low vision patients with the use of yoke prisms. Markowitz, SN., Teplitsky, JE., Taheri-Shirazi, M.[2021]

The Retinomax K-plus2 and plusoptiX S08 autorefractors are effective in detecting myopia, astigmatism, and anisometropia in children, showing high sensitivity compared to cycloplegic retinoscopy, especially after cycloplegia.

However, both devices tend to underestimate hyperopia when not used with cycloplegia, indicating a limitation in their accuracy for detecting significant hyperopic refractive errors.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Screening for refractive errors in children: the plusoptiX S08 and the Retinomax K-plus2 performed by a lay screener compared to cycloplegic retinoscopy. Paff, T., Oudesluys-Murphy, AM., Wolterbeek, R., et al.[2022]

The newly developed multiplexing prism (MxP) effectively expands the visual field for monocular patients by overcoming the limitations of apical scotomas, which conventional prisms cannot address.

Preliminary evaluations show that MxPs can significantly increase the nasal visual field in patients with conditions like hemianopia, suggesting a promising and cost-effective solution for enhancing vision in those with visual field loss.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Multiplexing Prisms for Field Expansion. Peli, E., Jung, JH.[2022]

Bifocal and trifocal designs for monovision corrections significantly enhance optical performance, providing a 5% improvement in optical quality and a 35% increase in through-focus usability compared to spherical aberration designs.

The study found that a bifocal design with a 1.5 diopter addition offers the best range of vision for near tasks, suggesting that combining monofocal and multifocal designs can optimize vision for individuals with presbyopia.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Optical properties of monovision corrections using multifocal designs for near vision. de Gracia, P.[2018]

A new type of prism made from a combination of planoconvex and planoconcave cylindrical lenses can adjust its strength continuously from 0 to 90 prism diopters, making it very versatile for various optical applications.

The study explores how the angle at which light hits the prism affects its power, which is important for understanding how to use this new prism effectively in different situations.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

[A variable prism]. Zhou, W., Wang, JP.[2008]

In a case series involving 12 patients with stable diplopia due to acquired strabismus, extreme pseudophakic monovision significantly reduced or eliminated double vision after cataract surgery.

This approach involved targeting one eye for clear distance vision and the other for myopia, resulting in excellent uncorrected vision for both distance and near tasks, suggesting a potential new strategy for managing diplopia in these patients.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Intentional extreme anisometropic pseudophakic monovision: new approach to the cataract patient with longstanding diplopia. Osher, RH., Golnik, KC., Barrett, G., et al.[2013]

Citations

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Multiplexing Prism Fitting for Field Expansion of Monocular ...

Multiplexing prism is designed for spatial vision multiplexing. It allows partial light transmission through the prism allow the observer to simultaneously see ...

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withpower.com/trial/phase-blindness-9-2023-8668e

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pmc.ncbi.nlm.nih.gov

pmc.ncbi.nlm.nih.gov/articles/PMC5542858/

Multiplexing Prisms for Field Expansion - PMC - PubMed Central

A newly invented optical device, the multiplexing prism (MxP), was developed to overcome the apical scotoma limitation in monocular field expansion.

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Field Expansion for Acquired Monocular Vision Using a ...

The shifted view from VN is determined by the effective prism power at VN of the tilted eyeward prism serration multiplexing prism segment. A ...

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Simulated Walking With Multiplexing Prism for Field ...

The investigators are developing an assistive device, known as multiplexing prism that expands the field of view for individuals with ...