To study changes of the visual field due to post-chiasmatic lesions and their relations with patient experiences.
ID
Source
Brief title
Condition
- Neurological disorders of the eye
Synonym
Research involving
Sponsors and support
Intervention
Outcome measures
Primary outcome
- Patient experiences: results on visual quality of life questionnaires
- Ophthalmological: result of non-invasive ophthalmological exam
- Psychophysical: performance on computer tasks (UFOV, Gabor detection,
Visual motion detection taak en scene recognition taak.)
Secondary outcome
Eye movement measured non-invasively with a video-based eye-tracker.
Background summary
Visual information processing is crucially important in daily life. This
becomes even more obvious when part of the visual field is damaged. Visual
field defects can occur as a result of post-chiasmatic brain damage for example
after vascular accidents, cranio-cerebral trauma, hypoxia or infections. These
patients, also called hemianopia patients, experience problems in daily life
for example in reading, visual navigation (during cycling and driving) and
visual identification (recognizing people and objects).
It is generally assumed that the *intact* visual field, i.e. the visual field
that does not differ from normal as measured by standard perimetry, is healthy.
Nevertheless, patients often complain about this part of the field as well.
Patients therefore seem to experience functional problems that cannot be
accounted for by light-sensitivity at these locations. Previous research has
shown that this field is indeed not completely normal. Differences were found
in contrast-sensitivity, response times and contour integration. Furthermore,
hemianopia patients were shown to experience more difficulty in search tasks,
also in the intact field.
Similarly, it is generally assumed that patients cannot use their blind field
functionally anymore. Previous studies have shown that this part of the visual
field can still process visual stimuli although it may be unconsciously. This
phenomenon is called *blind-sight* and shows that the blind field can still be
functional to a certain extent.
The current study will map the properties of both the intact visual field as
well as the defect visual field using psychophysical measurements. We will
mainly focus on temporal and spatial properties and their relations with
patient experiences.
Study objective
To study changes of the visual field due to post-chiasmatic lesions and their
relations with patient experiences.
Study design
Exploratory, Observational study where patients are compared to healthy adults.
Study burden and risks
We will measure neurological processes indirectly through non-invasive
psychophysical measurements. These measurements will take maximally 2 hours
each. All measures will be done in one day including breaks to ease the burden
for patients. We expect that the healthy subjects will need less time to
complete the study. The measures can be categorized into three categories:
questionnaires, psychophysics and non-invasive ophthalmological examination.
There are no risks involved in any of these measurements.
Patients do not immediately benefit when participating in this study. It does
however offer an opportunity to study (1) the neurophysiological properties of
the intact and defective visual field and (2) its relations with patient
experiences. It will therefore contribute to understanding consequences of
post-chiasmatic lesions.
Kapittelweg 29
Nijmegen 6525 EN
NL
Kapittelweg 29
Nijmegen 6525 EN
NL
Listed location countries
Age
Inclusion criteria
Patients:
- At least 18 years old.
- Patients with visual field defects as consequence of post-chiasmatic lesions.
- Normal or corrected-to-normal vision. ;Controls:
- At least 18 years old.
- Normal or corrected-to-normal vision.
Exclusion criteria
Patients:
* Presence of visual neglect (tested with character line bisection).
* Self-reported presence of other neurological, psychiatric or ocular impairments that might influence attention or the visual system.
Controls:
* Self-reported presence of neurological, psychiatric or ocular impairments that might influence attention or the visual system.
Design
Recruitment
Followed up by the following (possibly more current) registration
No registrations found.
Other (possibly less up-to-date) registrations in this register
No registrations found.
In other registers
| Register | ID |
|---|---|
| CCMO | NL58053.091.16 |