Clinical Trial of Multi-Periscopic Prism Glasses for Hemianopia

November 9, 2023 updated by: Eli Peli, Massachusetts Eye and Ear Infirmary

Randomized Controlled Multicenter Clinical Trial of Multi-Periscopic Prism Glasses for Homonymous Hemianopia

This clinical trial will evaluate the efficacy of two types of high-power prism glasses that provide field of view expansion for patients with homonymous hemianopia (the complete loss of half the field of vision on the same side in both eyes).

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Detailed Description

Patients with hemianopic field loss may be unaware of objects in their blind (non-seeing) hemi-field and often experience difficulties with hazards, such as walking into obstacles on the side of the field loss. Prism glasses that provide field of view expansion may be helpful in detecting hazards on the blind side. In this clinical trial, two types of high power prism glasses will be evaluated. A new design of prisms, Multi-Periscopic Prisms (MPP), will be compared to commercially-available permanent Fresnel peripheral prism (FPP) glasses. The extent to which the prismatic devices improve detection of hazards on the side of the field loss and are helpful when walking will be evaluated.

Participants will try each type of prism glasses at home for 4 weeks in counterbalanced order. Prism glasses will be fitted by Low Vision Practitioners at vision rehabilitation clinics. Participants will attend in-office study visits before and after wearing each type of prism glasses. At the in-office visits they will complete a test that involves detecting pedestrian hazards in a video simulating a walk through a busy shopping mall (virtual reality, VR, walking simulator test). In addition, they may be asked to complete questionnaires to record their experiences of using the prism glasses.

After wearing the second pair of prism glasses, participants will be asked to complete a questionnaire comparing the two types of prism glasses and to select their preferred type. A clinical decision will be made as to whether the participant should continue to use either the first or second pair of prism glasses (e.g. if a participant finds one pair of prism glasses helpful for obstacle avoidance when walking). For participants who continue with the prism glasses, telephone follow-up interviews will be conducted after about 6 and 12 months.

Study Type

Interventional

Enrollment (Estimated)

65

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Locations

  • United States
    • Alabama
      • Birmingham, Alabama, United States, 35233
        • Recruiting
        • UAB Center for Low Vision Rehabilitation, Callahan Eye Hospital
        • Contact:
    • Colorado
      • Denver, Colorado, United States, 80045
    • Florida
      • Palm Springs, Florida, United States, 33461
        • Recruiting
        • Visual Health and Surgical Center
        • Contact:
    • Illinois
      • Chicago, Illinois, United States, 60616
        • Recruiting
        • Illinois College of Optometry
        • Contact:
    • Massachusetts
      • Boston, Massachusetts, United States, 02114
      • Boston, Massachusetts, United States, 02215
        • Recruiting
        • New England College of Optometry
        • Contact:
      • Worcester, Massachusetts, United States, 01655
      • Worcester, Massachusetts, United States, 01608
        • Not yet recruiting
        • The Eye and Vision Center at MCPHS
        • Contact:

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

7 years and older (Child, Adult, Older Adult)

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Homonymous hemianopia with or without macular sparing for at least 6 months
  • Visual acuity of at least 20/50 in each eye, with correction if needed
  • Refractive error in the -12D to +5D range
  • Able to walk independently, using a cane or walker if needed
  • Able to communicate in English sufficiently to understand the study procedures and how to use the prisms

Exclusion Criteria:

  • Central visual field loss in the seeing hemifield of either eye (e.g. from macular degeneration, glaucoma, diabetic retinopathy or other maculopathies)
  • Hemi-spatial neglect
  • Significant cognitive impairment
  • Dementia
  • Any other physical or mental disabilities, or general health problems that could impair the ability to be independently mobile (i.e., walk ), participate in the VR walking simulator test or use the prism glasses

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Crossover Assignment
  • Masking: Single

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: MPP first, FPP second
Participants in this arm will receive the MPP in the first period of the crossover and the FPP in the second period.
Device: Multi-Periscopic Prism (MPP) glasses
Spectacles with multi-periscopic prisms mounted as oblique peripheral prism segments
Device: Fresnel Peripheral Prism (FPP) glasses
Spectacles with conventional permanent Fresnel prisms mounted as oblique peripheral prism segments
Experimental: FPP first, MPP second
Participants in this arm will receive the FPP in the first period of the crossover and the MPP in the second period.
Device: Multi-Periscopic Prism (MPP) glasses
Spectacles with multi-periscopic prisms mounted as oblique peripheral prism segments
Device: Fresnel Peripheral Prism (FPP) glasses
Spectacles with conventional permanent Fresnel prisms mounted as oblique peripheral prism segments

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Change in detection rate for hazards approaching from the blind side in the VR walking simulator test
Time Frame: Baseline, After 4 weeks of wearing first pair of prism glasses, After 4 weeks of wearing second pair of prism glasses
Number of pedestrians detected as a percentage of the total number of pedestrian events.
Baseline, After 4 weeks of wearing first pair of prism glasses, After 4 weeks of wearing second pair of prism glasses

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Change in detection response time for hazards approaching from the blind side in the VR walking simulator test
Time Frame: Baseline, After 4 weeks of wearing first pair of prism glasses, After 4 weeks of wearing second pair of prism glasses
Response time from pedestrian target onset to the first button press to indicate detection
Baseline, After 4 weeks of wearing first pair of prism glasses, After 4 weeks of wearing second pair of prism glasses
Device preference
Time Frame: After 4 weeks of wearing the second pair of prism glasses
Number of participants selecting each device as a percentage of the total number of participants enrolled
After 4 weeks of wearing the second pair of prism glasses
Continuation rate (at end of crossover)
Time Frame: After 4 weeks of wearing the second pair of prism glasses
Number of participants with a clinical decision to continue with prism glasses at the end of the crossover as a percentage of the total number of participants enrolled.
After 4 weeks of wearing the second pair of prism glasses
Continuation rate (long term)
Time Frame: At 6 months
Number of participants still wearing prism glasses as a percentage of total number of participants enrolled.
At 6 months

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Massachusetts Eye and Ear Infirmary

Collaborators

National Eye Institute (NEI)

Investigators

  • Principal Investigator: Eli Peli, OD MSc, Schepens Eye Research Institute of Massachusetts Eye and Ear

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

October 3, 2022

Primary Completion (Estimated)

June 1, 2024

Study Completion (Estimated)

September 1, 2024

Study Registration Dates

First Submitted

March 25, 2021

First Submitted That Met QC Criteria

March 31, 2021

First Posted (Actual)

April 1, 2021

Study Record Updates

Last Update Posted (Estimated)

November 13, 2023

Last Update Submitted That Met QC Criteria

November 9, 2023

Last Verified

November 1, 2023

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • MPPvsFPP
  • R01EY023385 (U.S. NIH Grant/Contract)

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

Yes

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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