Feasibility Tests for Various Prism Configurations for Visual Field Loss

NCT04424979 — Not applicable, Completed, 10 participants, Massachusetts Eye and Ear Infirmary

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Visual Field Expansion Through Innovative Multi-Periscopic Prism Design

Registry	NCT04424979
Status	Completed
Phase	Not applicable
Study type	Interventional; na, single group, masking: none, device feasibility
Enrollment	10 (Actual)
Sponsor	Massachusetts Eye and Ear Infirmary (Other); collaborators: National Eye Institute (NEI)
Conditions	Hemianopia, Homonymous, Tunnel Vision, Visual Field Defect, Peripheral, Visual Field Constriction Bilateral, Visual Field Defect Homonymous Bilateral
Interventions	High power prisms (Device)
Dates	start 2020-11-06, primary completion 2026-06-30, completion 2026-09-30, first posted 2020-06-11, last updated 2026-10-06
Locations	1 site in United States

-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.

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+Arms and interventions

Arm	Type	Interventions	Description
High power prisms	Experimental	Device: High power prisms	Various configurations of high power prisms will be developed for each individual and custom fit into spectacles lenses.

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

+Outcome measures

Primary outcomes

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 outcomes

Pedestrian detection rate [Through study completion, an average of four months]: Proportion of pedestrians detected (in simulated walking or simulated driving)

+Eligibility

Sex: All, ages: 7 Years to 80 Years

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)

+Locations (1)

Facility	City	Country	Status
Schepens Eye Research Institute	Boston, Massachusetts	United States

+Publications

Results publication: 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

+Investigators

Eliezer Peli, MSc, OD, Study director, Schepens Eye Research Institute of Massachusetts Eye and Ear

+Funding

NIH grants: R01EY023385

My Notes

Public

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