Homonymous Hemianopia
Conditions
Brief 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).
Detailed 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.
Interventions
DEVICEMulti-Periscopic Prism (MPP) glasses
Spectacles with multi-periscopic prisms mounted as oblique peripheral prism segments
DEVICEFresnel Peripheral Prism (FPP) glasses
Spectacles with conventional permanent Fresnel prisms mounted as oblique peripheral prism segments
Sponsors
Massachusetts Eye and Ear Infirmary
National Eye Institute (NEI)
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
TREATMENT
Masking
SINGLE (Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Age
7 Years to No maximum
Healthy volunteers
No
Inclusion criteria
* Homonymous hemianopia with or without macular sparing for at least 3 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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Improvement in Blind-side Detection Rate for Hazards Approaching at a Bearing Angle of 40 Degrees | Immediately after each 4-week intervention | Improvement in detection rate with prism glasses for hazards approaching from the blind side at a bearing angle of 40 degrees in the VR walking simulator test. Improvement is a binary outcome, defined as blind-side detection rate (number of pedestrians detected as a percentage of the total number of pedestrian events) which is significantly higher (z-test for two proportions) with than without prism glasses at the same visit. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Improvement in Blind-side Detection Rate for Hazards Approaching at a Bearing Angle of 20 Degrees | Immediately after each 4-week intervention | Improvement in detection rate with prism glasses for hazards approaching from the blind side at a bearing angle of 20 degrees in the VR walking simulator test. Improvement is a binary outcome, defined as blind-side detection rate (number of pedestrians detected as a percentage of the total number of pedestrian events) which is significantly higher (z-test for two proportions) with than without prism glasses at the same visit. |
| Device Preference | Immediately after the second 4-week intervention | Number of participants selecting each device as a percentage of the total number of participants enrolled |
Countries
United States
Contacts
PRINCIPAL_INVESTIGATOREli Peli, OD MSc
Schepens Eye Research Institute of Massachusetts Eye and Ear
Participant flow
Recruitment details
Participants were recruited between April 2023 and November 2024 at seven vision rehabilitation clinics in the United States, including three university clinics, three academic medical centers and one private practice.
Pre-assignment details
64 participants were screened. 26 did not meet eligibility criteria and were excluded All 38 participants who met eligibility criteria were allocated to receive either MPP first (n=19) or FPP first (n=19). One allocation was mistakenly swopped; therefore 18 participants started in the MPP first group and 20 in the FPP first group.
Baseline characteristics
| Characteristic | — |
|---|---|
| Age, Continuous | 57 Years |
| Ethnicity (NIH/OMB) Hispanic or Latino | 3 Participants |
| Ethnicity (NIH/OMB) Not Hispanic or Latino | 17 Participants |
| Ethnicity (NIH/OMB) Unknown or Not Reported | 0 Participants |
| Race (NIH/OMB) American Indian or Alaska Native | 0 Participants |
| Race (NIH/OMB) Asian | 0 Participants |
| Race (NIH/OMB) Black or African American | 4 Participants |
| Race (NIH/OMB) More than one race | 0 Participants |
| Race (NIH/OMB) Native Hawaiian or Other Pacific Islander | 0 Participants |
| Race (NIH/OMB) Unknown or Not Reported | 3 Participants |
| Race (NIH/OMB) White | 29 Participants |
| Sex: Female, Male Female | 4 Participants |
| Sex: Female, Male Male | 13 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | 0 / 38 | 0 / 38 |
| other Total, other adverse events | 0 / 38 | 0 / 38 |
| serious Total, serious adverse events | 0 / 38 | 0 / 38 |
Outcome results
None listed