Feasibility Tests for Various Prism Configurations for Visual Field Loss

NCT04424979 | Recruiting FDA Device

• 2 other identifiers: MPP_Feasibility1R01EY023385
• Study Type: interventional
• Target: 20
• Locations: 1 country
• Sites: 1

Brief Summary

The investigators will develop and test different configurations of high-power prisms to expand the field of vision of patients with visual field loss to assist them with obstacle detection when walking. The study will involve multiple visits (typically four) to Schepens Eye Research Institute for fitting and testing with the prism glasses. The overall objective is to determine best designs and fitting parameters for implementation in prism devices for future clinical trials.

Conditions

Hemianopia, Homonymous; Tunnel Vision; Visual Field Defect, Peripheral; Visual Field Constriction Bilateral; Visual Field Defect Homonymous Bilateral

Keywords

Visual field expansion; Prisms; Hemianopsia; Tunnel vision; Visual field loss

Outcome Measures

Primary Outcomes (1)

• Field of view expansion

  Horizontal and vertical extent of the expansion (in degrees) of the field of view

  Through study completion, an average of four months

Secondary Outcomes (1)

• Pedestrian detection rate

  Through study completion, an average of four months

Study Arms (1)

High power prisms

EXPERIMENTAL

Various configurations of high power prisms will be developed for each individual and custom fit into spectacles lenses.

Device: High power prisms

Interventions

High power prisms DEVICE

High power prisms designed to shift images from blind areas into portions of the wearer's remaining, seeing, field of vision

High power prisms

Eligibility Criteria

• Age: 7 Years - 80 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Child (0-17), Adult (18-64), Older Adult (65+)

You may qualify if:

• Visual field loss, either peripheral field loss or hemianopic field loss
• Visual acuity of at least 20/50 in the better eye
• In sufficiently good health to be able to complete sessions lasting 2-4 hours
• Able to independently walk short distances
• Able to give voluntary, informed consent
• Able to speak English

You may not qualify if:

• Any physical or mental impairments, including cognitive dysfunction, balance problems or other deficits that could impair the ability to walk or use the prism spectacles
• A history of seizures in the last 6 months
• Hemispatial neglect (subjects with hemianopic field loss only)

Sponsors & Collaborators

• Massachusetts Eye and Ear Infirmary: lead
• National Eye Institute (NEI): collaborator

Study Sites (1)

Schepens Eye Research Institute

Boston, Massachusetts, 02114, United States

RECRUITING

Related Publications (1)

• Bowers AR, Manda S, Shekar S, Hwang AD, Jung JH, Peli E. Pilot study of a pedestrian collision detection test for a multisite trial of field expansion devices for hemianopia. Optom Vis Sci. 2024 Jun 1;101(6):408-416. doi: 10.1097/OPX.0000000000002152.

  PMID: 38990239 DERIVED

MeSH Terms

Conditions

Hemianopsia

Condition Hierarchy (Ancestors)

Vision Disorders; Sensation Disorders; Neurologic Manifestations; Nervous System Diseases; Blindness; Eye Diseases; Signs and Symptoms; Pathological Conditions, Signs and Symptoms

Study Officials

• Eliezer Peli, MSc, OD

  Schepens Eye Research Institute of Massachusetts Eye and Ear

  STUDY DIRECTOR

Central Study Contacts

Alex Bowers

CONTACT

617 912 2512; alex_bowers@meei.harvard.edu

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NA
• Masking: NONE
• Purpose: DEVICE FEASIBILITY
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Associate Professor

Study Record Dates

• First Submitted: June 5, 2020
• First Posted: June 11, 2020
• Study Start: November 6, 2020
• Primary Completion (Estimated): August 1, 2026
• Study Completion (Estimated): December 1, 2026
• Last Updated: September 23, 2025

Record last verified: 2025-09

Data Sharing

• IPD Sharing: Will not share

Locations

US (1)