Clinical Trial Details
— Status: Terminated
Administrative data
| NCT number |
NCT04156763 |
| Other study ID # |
268329 (100-06-19) |
| Secondary ID |
|
| Status |
Terminated |
| Phase |
|
| First received |
|
| Last updated |
|
| Start date |
June 22, 2020 |
| Est. completion date |
June 8, 2022 |
Study information
| Verified date |
December 2023 |
| Source |
Norfolk and Norwich University Hospitals NHS Foundation Trust |
| Contact |
n/a |
| Is FDA regulated |
No |
| Health authority |
|
| Study type |
Observational
|
Clinical Trial Summary
Strabismus, or squint, describes any misalignment of the eyes, and can affect both children
and adults. As a result, the images of the outside world conveyed to the brain from the two
eyes do not correspond, which can result in diplopia, or 'double vision'. As well as
impacting on a patient's functionality, strabismus can have cosmetic and psychosocial
ramifications. Furthermore, if left untreated in childhood, strabismus can lead to life-long
visual impairment, despite best spectacle correction.
Current treatment is guided by the exact nature of the strabismus and the patient's age;
options include spectacle prescription to correct underlying refractive error, use of prisms
to control deviation, or in certain cases, surgery. In order to investigate the size and type
of strabismus present, and determine the best management, tests of ocular deviation are
performed in Eye Clinics.
Quantitative objective assessment of the angle of horizontal and vertical strabismus is
currently performed using the prism cover test - the patient is asked to look at a fixation
target, and prisms of increasing power are placed in front of one eye until the ocular
deviation is neutralised (i.e. there is no movement of the eyes to take up fixation). The
test can provide accurate numerical recordings to aid in monitoring and surgical planning.
However, the prism cover test requires a range of different prisms, the presence of a near
and distance fixation target, a trained examiner, and a patient able to fixate at an
appropriate target without moving their head for the duration of the test. In this study, it
will be investigated whether a virtual reality headset-based test can produce comparable
measurements of ocular deviation to the traditional prism cover test, without the need for
prisms, or control of head posture.
Description:
Purpose
1. To establish whether a virtual reality headset-based test can produce accurate and
reliable data on ocular deviation in those with disturbances of ocular motility, by
comparing its performance to those of established tests of ocular deviation currently in
use in clinical practice (prism cover test).
2. To assess the practicality, and subjective experience of a virtual reality headset-
based Lancaster red-green test, using questionnaire surveys
Background
Strabismus, or squint, describes any misalignment of the eyes, and can affect both children
and adults. As a result, the images of the outside world conveyed to the brain from the two
eyes do not correspond, which can result in diplopia, or 'double vision'. As well as
impacting on a patient's functionality, strabismus can have cosmetic and psychosocial
ramifications. Furthermore, if left untreated in childhood, strabismus can lead to life-long
visual impairment, despite best spectacle correction.
Current treatment is guided by the exact nature of the strabismus and the patient's age;
options include spectacle prescription to correct underlying refractive error, use of prisms
to control deviation, or in certain cases, surgery. In order to investigate the size and type
of strabismus present, and determine the best management, tests of ocular deviation are
performed in Eye Clinics.
Quantitative objective assessment of the angle of horizontal and vertical strabismus is
currently performed using the prism cover test - the patient is asked to look at a fixation
target, and prisms of increasing power are placed in front of one eye until the ocular
deviation is neutralised (i.e. there is no movement of the eyes to take up fixation). The
test can provide accurate numerical recordings to aid in monitoring and surgical planning.
However, the prism cover test requires a range of different prisms, the presence of a near
and distance fixation target, a trained examiner, and a patient able to fixate at an
appropriate target without moving their head for the duration of the test. In this study, it
will be investigated whether a virtual reality headset-based test can produce comparable
measurements of ocular deviation to the traditional prism cover test, without the need for
prisms, or control of head posture.
Design and Methodology
Research participants will be recruited from the pool of patients presenting to the Eye
department for their regular appointment.
Those who meet the inclusion criteria will have the study explained to them by a member of
the research team in the department, and given a leaflet to read about the study. Should they
wish to take part, they will have verbal and written consent taken, and then undergo two
tests:
1. Prism cover test
2. Virtual reality headset-based test
Each test will last approximately 10 minutes. At the end of the two tests, they will be asked
to fill in a questionnaire on their experience of the tests. They will require no additional
visits to clinic as part of enrolling in the study.
Statistical Analysis
The angles of deviation of the eyes will be extracted from each of the three tests, and Bland
Altman analysis will be applied to the data to check for agreement.
The subjective experience of the virtual reality headset-based Lancaster red-green test
measured by the questionnaire, and compared to the subjective experience of the two
established tests of ocular deviation using a paired t-test.
