Visual processing speed in hemianopia patients secondary to acquired brain injury: a new assessment methodology.
Laura Mena-Garcia, Miguel J Maldonado-Lopez, Itziar Fernandez and 5 others
PMID 32005265WHAT IT FOUND
People with visual field loss after brain injury were 73.0% slower at finding and touching everyday objects than matched healthy people.
A timed search-and-reach task may help therapists see how field loss affects daily visual tasks.
Key findings
01Patients with acquired brain injury and homonymous visual field defects were 73.0% slower on the new visual processing speed test than matched healthy controls.
02The brain injury group made 335.6% more eye-hand coordination mistakes and were 41.3% more inaccurate when reaching than controls.
03Within the brain injury group, speed was similar when searching on the blind side and the healthy side of the visual field.
STILL TO COME
How it was doneWhat they foundWhat it means for OTs
Read the rest of this summary
You get three full summaries a month, free, and we do not ask for a card. Search, the TL;DRs and your library stay unlimited either way.
What it does not show
No rehabilitation treatment was tested, so the study cannot show whether slower speed predicts benefit from therapy or whether the test can measure therapy change. The study required far binocular visual acuity of at least 0.1 LogMAR, and excluded visual neglect, visual agnosia, cognitive deficit, or insufficient hearing or hand-arm ability. Patients had to be clinically stable at least 3 months after brain injury, so results may not apply to the early post-injury period. The system did not include an eye tracker, so it cannot confirm that the person actually looked at the correct stimulus during the search step. A subject could press the button without seeing the stimulus; the reach step and error measures were used to detect this, but not all false search times are eliminated. All participants were assessed in a single visit, so the study does not show how repeatable the results are.
The easy way to misread this
Do not read the slower speed as proof that a rehabilitation programme works or fails. The study only compared people with visual field defects to healthy people at one time; it did not give any treatment or test change over time.