Visual training of cerebral blindness patients gradually enlarges the visual field.
BACKGROUND
Multiple studies on recovery of hemianopsia after cerebrovascular accident report visual-field enlargements after stimulation of the visual-field border area. These enlargements are made evident by the difference between pre- and post-training measurements of the visual field. Until now, it was not known how the visual-field enlargement develops.


OBJECTIVE
To study how the enlargement develops as a function of time.


METHODS
11 subjects were trained by stimulating the border area of their visual-field defect using a Goldmann perimeter. The visual-field border location was assessed using dynamic Goldmann perimetry before, after and during training (after each 10th training session). To monitor eye fixation, a video-based eye-tracker was used during each complete perimetry session.


RESULTS
It was found that visual-field enlargement during training is actually a gradual shift of the visual-field border, which was independent of the type of stimulus-set used during training. The shift could be observed while eye fixation was accurate.


CONCLUSIONS
Visual-detection training leads to a decrease in detection thresholds in the affected visual-field areas and to visual-field enlargement. Training effects can be generalised to important daily-life activities like reading.
Bergsma
D P
DP
Kruytgebouw, Room N-201, Padualaan 8, 3584 CH, Utrecht, The Netherlands. d.p.bergsma@uu.nl
van der Wildt
G
G
D000368:Aged; D053483:Eye Movement Measurements; D005133:Eye Movements / Q000502:physiology; D005260:Female; D005793:Generalization, Psychological; D006423:Hemianopsia / Q000209:etiology / Q000503:physiopathology / Q000534:rehabilitation*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010775:Photic Stimulation / Q000379:methods; D011214:Practice, Psychological; D011932:Reading; D012684:Sensory Thresholds / Q000502:physiology; D017603:Signal Detection, Psychological / Q000502:physiology; D020521:Stroke / Q000150:complications; D015349:Vision, Monocular / Q000502:physiology; D058609:Visual Field Tests / Q000379:methods; D014794:Visual Fields / Q000502:physiology*