I don't have agoraphobia but I found this interesting site here which said:
Which makes me wonder, do any of you have poor balance, get disoriented, dizzy or motion sickness easily ?The Visual-Spatial Connection
Research has also unearthed unexpected but clear connections between agoraphobia and problems involving spatial orientation and visual-spatial data processing as well. Studies involving responses to virtual reality experiences have shown that those with agoraphobia tend to show higher rates of impaired processing when dealing with shifting audiovisual data. Even common everyday geometrical planes can prove challenging: sloping, irregular are less easily gauged by agoraphobics and may cause confusion.
A disproportionate large number of those who suffer from agoraphobia also have weak vestibular function, a brain process whereby visual processing and spatial orientation significantly contribute to balance and spatial coordination. Those whose vestibular functions are weak are more dependent upon visual or tactile signals in the immediate environment to orient themselves. When such cues are sparse, as in vast open empty spaces, or when they come as a relentless cataract of impressions, as in crowd situations, the result is a disorientation that, for the agoraphobic, can lead easily to panic.