Feasibility Tests for Various Prism Configurations for Visual Field Loss

Visual Field Defect, Peripheral Clinical Trial

Official title:

Visual Field Expansion Through Innovative Multi-Periscopic Prism Design

Clinical Trial Details — Status: Recruiting

Administrative data

• NCT number: NCT04424979
• Other study ID #: MPP_Feasibility1
• Secondary ID: R01EY023385
• Status: Recruiting
• Phase: N/A
• Start date: November 6, 2020
• Est. completion date: August 2024

Study information

• Verified date: March 2024
• Source: Massachusetts Eye and Ear Infirmary
• Contact: Sailaja Manda
• Phone: 617 912 2522
• Email: sailaja_manda[@]meei.harvard.edu
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial 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.

Recruitment information / eligibility

• Status: Recruiting
• Enrollment: 20
• Est. completion date: August 2024
• Est. primary completion date: August 2024
• Accepts healthy volunteers: No
• Gender: All
• Age group: 7 Years to 80 Years

Eligibility

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)

Related Conditions & MeSH terms

• Constriction, Pathologic
• Hemianopia, Homonymous
• Hemianopsia
• Tunnel Vision
• Visual Field Constriction Bilateral
• Visual Field Defect Homonymous Bilateral
• Visual Field Defect, Peripheral

Intervention

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

Locations

Country	Name	City	State
United States	Schepens Eye Research Institute	Boston	Massachusetts

Sponsors (2)

Lead Sponsor	Collaborator
Massachusetts Eye and Ear Infirmary	National Eye Institute (NEI)

Country where clinical trial is conducted

United States, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	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	Pedestrian detection rate	Proportion of pedestrians detected (in simulated walking or simulated driving)	Through study completion, an average of four months