Clinical Trial of Multi-Periscopic Prism Glasses for Hemianopia

Homonymous Hemianopia Clinical Trial

Official title:

Randomized Controlled Multicenter Clinical Trial of Multi-Periscopic Prism Glasses for Homonymous Hemianopia

Clinical Trial Details — Status: Recruiting

Administrative data

• NCT number: NCT04827147
• Other study ID #: MPPvsFPP
• Secondary ID: R01EY023385
• Status: Recruiting
• Phase: N/A
• Start date: October 3, 2022
• Est. completion date: September 1, 2024

Study information

• Verified date: November 2023
• Source: Massachusetts Eye and Ear Infirmary
• Contact: Alex Bowers, PhD
• Phone: 617-912-2512
• Email: alex_bowers[@]meei.harvard.edu
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

This clinical trial will evaluate the efficacy of two types of high-power prism glasses that provide field of view expansion for patients with homonymous hemianopia (the complete loss of half the field of vision on the same side in both eyes).

Description:

Patients with hemianopic field loss may be unaware of objects in their blind (non-seeing) hemi-field and often experience difficulties with hazards, such as walking into obstacles on the side of the field loss. Prism glasses that provide field of view expansion may be helpful in detecting hazards on the blind side. In this clinical trial, two types of high power prism glasses will be evaluated. A new design of prisms, Multi-Periscopic Prisms (MPP), will be compared to commercially-available permanent Fresnel peripheral prism (FPP) glasses. The extent to which the prismatic devices improve detection of hazards on the side of the field loss and are helpful when walking will be evaluated.

Participants will try each type of prism glasses at home for 4 weeks in counterbalanced order. Prism glasses will be fitted by Low Vision Practitioners at vision rehabilitation clinics. Participants will attend in-office study visits before and after wearing each type of prism glasses. At the in-office visits they will complete a test that involves detecting pedestrian hazards in a video simulating a walk through a busy shopping mall (virtual reality, VR, walking simulator test). In addition, they may be asked to complete questionnaires to record their experiences of using the prism glasses.

After wearing the second pair of prism glasses, participants will be asked to complete a questionnaire comparing the two types of prism glasses and to select their preferred type. A clinical decision will be made as to whether the participant should continue to use either the first or second pair of prism glasses (e.g. if a participant finds one pair of prism glasses helpful for obstacle avoidance when walking). For participants who continue with the prism glasses, telephone follow-up interviews will be conducted after about 6 and 12 months.

Recruitment information / eligibility

• Status: Recruiting
• Enrollment: 65
• Est. completion date: September 1, 2024
• Est. primary completion date: June 1, 2024
• Accepts healthy volunteers: No
• Gender: All
• Age group: 7 Years and older

Eligibility

Inclusion Criteria:

• Homonymous hemianopia with or without macular sparing for at least 6 months

• Visual acuity of at least 20/50 in each eye, with correction if needed

• Refractive error in the -12D to +5D range

• Able to walk independently, using a cane or walker if needed

• Able to communicate in English sufficiently to understand the study procedures and how to use the prisms

Exclusion Criteria:

• Central visual field loss in the seeing hemifield of either eye (e.g. from macular degeneration, glaucoma, diabetic retinopathy or other maculopathies)

• Hemi-spatial neglect

• Significant cognitive impairment

• Dementia

• Any other physical or mental disabilities, or general health problems that could impair the ability to be independently mobile (i.e., walk ), participate in the VR walking simulator test or use the prism glasses

Related Conditions & MeSH terms

• Hemianopsia
• Homonymous Hemianopia

Intervention

Device:
• Multi-Periscopic Prism (MPP) glasses
Spectacles with multi-periscopic prisms mounted as oblique peripheral prism segments
• Fresnel Peripheral Prism (FPP) glasses
Spectacles with conventional permanent Fresnel prisms mounted as oblique peripheral prism segments

Locations

Country	Name	City	State
United States	UAB Center for Low Vision Rehabilitation, Callahan Eye Hospital	Birmingham	Alabama
United States	New England College of Optometry	Boston	Massachusetts
United States	Schepens Eye Research Institute	Boston	Massachusetts
United States	Illinois College of Optometry	Chicago	Illinois
United States	UCHealth Sue Anschutz-Rodgers Eye Center	Denver	Colorado
United States	Visual Health and Surgical Center	Palm Springs	Florida
United States	The Eye and Vision Center at MCPHS	Worcester	Massachusetts
United States	UMass Chan Medical School	Worcester	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	Change in detection rate for hazards approaching from the blind side in the VR walking simulator test	Number of pedestrians detected as a percentage of the total number of pedestrian events.	Baseline, After 4 weeks of wearing first pair of prism glasses, After 4 weeks of wearing second pair of prism glasses
Secondary	Change in detection response time for hazards approaching from the blind side in the VR walking simulator test	Response time from pedestrian target onset to the first button press to indicate detection	Baseline, After 4 weeks of wearing first pair of prism glasses, After 4 weeks of wearing second pair of prism glasses
Secondary	Device preference	Number of participants selecting each device as a percentage of the total number of participants enrolled	After 4 weeks of wearing the second pair of prism glasses
Secondary	Continuation rate (at end of crossover)	Number of participants with a clinical decision to continue with prism glasses at the end of the crossover as a percentage of the total number of participants enrolled.	After 4 weeks of wearing the second pair of prism glasses
Secondary	Continuation rate (long term)	Number of participants still wearing prism glasses as a percentage of total number of participants enrolled.	At 6 months