Abstract
Purpose:
Homonymous hemianopia (HH), the loss of vision on one side in both eyes, is a frequent consequence of post-chiasmal lesions from conditions such as stroke. Under many definitions (e.g. classification systems), HH is not considered a visual impairment. We examined the disability caused by HH, and compared it to central vision loss (CVL) and normal vision (NV).
Methods:
Three studies are reported: (1) A survey about experiences with television, computers, hand-held video devices, movies at the cinema, and photography compared HH, (n=78) to NV (n=157) and CVL (n=113); (2) Measurement of the information acquired from video (the ability to follow and describe the story) compared HH (n=9) to NV (n=75) and CVL (n=12) using an objective, computational-linguistics analysis of the free-recall, natural-language responses; (3) perceived vision-related ability using the independent mobility questionnaire (IMQ) and the NEI-VFQ 25 (HH, n=196) evaluated using Rasch analysis.
Results:
People with HH were more likely to report difficulty watching television (p=0.006) or movies (p=0.001), and were less likely to go to cinema (p=0.003) or take photographs (p<0.001) than people with NV. Six (67%) of the subjects with HH had difficulty obtaining information from video (below 95% CI for NV), with a reduction in information acquisition similar to people with CVL, despite “normal” visual acuity and gaze patterns that were similar to people with NV. People with HH reported most difficulty with driving, noticing objects on the side, crowded situations, tasks that are up close, and finding items on a shelf (most negative item measures). They also report adverse mental and emotional effects due to their vision loss such as getting frustrated a lot, and feeling limited in their activities.
Conclusions:
People with HH often have and report substantial disability, with wide variations between individuals. These disabilities suggest that HH should be considered a vision impairment.