Recruiting

Observational Study

Sponsor:

Massachusetts Eye and Ear Infirmary

Code:

NCT04424979

Conditions

Hemianopia, Homonymous

Tunnel Vision

Visual Field Defect, Peripheral

Visual Field Constriction Bilateral

Visual Field Defect Homonymous Bilateral

Eligibility Criteria

Sex: All

Age: 7 - 70+

Healthy Volunteers: Not accepted

Interventions

High power prisms

Study Details

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

Study ID

NCT04424979

Start date

Nov 6, 2020

Status verified date

Sep, 2025

Completion date

Dec, 2026

Anticipated

Primary completion date

Aug, 2026

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 7 - 70+

Healthy Volunteers: Not accepted

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)

Study Design

Enrollment

20 participants

Anticipated

Intervention Model

Single group

Primary purpose

Device Feasibility

Interventions and Outcome Measures

Arms

experimental: High power prisms

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

Interventions

High power prisms

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

Primary outcome measure

  • Field of view expansion [ Time Frame: Through study completion, an average of four months ]

Central Contacts and Locations

Central contacts

Alex Bowers

617 912 2512alex_bowers@meei.harvard.edu

Locations

Schepens Eye Research Institute

Recruiting

Boston, Massachusetts, United States, 02114

More Information

Sponsor

Massachusetts Eye and Ear Infirmary

Last update posted

Sep 23, 2025

Last verified

Sep, 2025

Keywords

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

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-10. This information was provided to ClinicalTrials.gov by Massachusetts Eye and Ear Infirmary on 2025-09-23.