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NCT Number: NCT04424979

Feasibility Tests for Various Prism Configurations for Visual Field Loss

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.

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Key information

Conditions

Hemianopia, Homonymous Blindness Eye Diseases Hemianopsia Nervous System Diseases Neurologic Manifestations Pathological Conditions, Signs and Symptoms Sensation Disorders Signs and Symptoms Tunnel Vision Vision Disorders Visual Field Constriction Bilateral Visual Field Defect Homonymous Bilateral Visual Field Defect, Peripheral

Age range

7 year–80 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Schepens Eye Research Institute

Boston, Massachusetts, 02114, United States

Location status: Recruiting

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • 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

Exclusion criteria

  • 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)

Treatment and study plan

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

Primary outcomes

  1. Field of view expansion

    Time frame: Through study completion, an average of four months

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

Secondary outcomes

  1. Pedestrian detection rate

    Time frame: Through study completion, an average of four months

    Proportion of pedestrians detected (in simulated walking or simulated driving)

Study contacts

Contact information is provided by the study sponsor or research team.

Alex Bowers

CONTACT

[email protected]

617 912 2512

Sponsors and collaborators

Lead sponsor

Massachusetts Eye and Ear Infirmary

Other

Collaborators

  • National Eye Institute (NEI)

Registry information

Official study title

Visual Field Expansion Through Innovative Multi-Periscopic Prism Design

Important dates

Study start
2020
Primary completion
2026
Study completion
2026
First posted
Jun 11, 2020
Registry last updated
Sep 23, 2025

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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