Feasibility Tests for Various Prism Configurations for Visual Field Loss

Not Applicable

Recruiting

• Conditions: Hemianopia, Homonymous; Visual Field Defect, Peripheral; Visual Field Constriction Bilateral; Tunnel Vision; Visual Field Defect Homonymous Bilateral
• Interventions: Device: High power prisms

• Registration Number: NCT04424979
• Lead Sponsor: Massachusetts Eye and Ear Infirmary

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.

Detailed Description

Not available

Study Timeline

• Study First Submitted: 2020-06-05
• Study First Submitted QC: 2020-06-08
• Study First Posted: 2020-06-11
• Study Start: 2020-11-06
• Status Verified: 2024-03
• Last Update Submitted: 2024-03-11
• Last Update Posted: 2024-03-13
• Primary Completion: 2024-08
• Study Completion: 2024-08

Recruitment & Eligibility

• Status: RECRUITING
• Sex: All
• Target Recruitment: 20

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

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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)

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Study & Design

• Study Type: INTERVENTIONAL
• Study Design: SINGLE_GROUP

Arm && Interventions

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

Primary Outcome Measures

Name	Time	Method
Field of view expansion	Through study completion, an average of four months	Horizontal and vertical extent of the expansion (in degrees) of the field of view

Secondary Outcome Measures

Name	Time	Method
Pedestrian detection rate	Through study completion, an average of four months	Proportion of pedestrians detected (in simulated walking or simulated driving)

Trial Locations

Locations (1)

Schepens Eye Research Institute; 🇺🇸 Boston, Massachusetts, United States