Abstract
Purpose: :
This study investigated whether self-reported visual function in certain activities of daily living (ADL) was more strongly associated with observed compensated or standardised performance in the same tasks in individuals with visual impairment because it has been suggested that self-report is more based on the level of vision loss rather than on habitual function.
Methods: :
25 participants (14 macular disorder, 11 age-matched visually normal) were asked to self-report their habitual visual difficulty with three ADL: pouring liquid, putting a key into a lock, and identifying food on a plate. Self-reported difficulty was then compared to actual performance in the same tasks, which was assessed by an observer and graded on a 5-point scale (no difficulty to impossible) under two conditions: 1) participants performed the task habitually and as naturally as possible using any compensatory strategies, and 2) the tasks were performed under standardised conditions without the use of any compensatory strategies.
Results: :
The visually impaired self-reported significantly worse function in all three ADL and were observed to perform less well both under compensated and standardised conditions compared to the visually normal group (2-tailed Mann-Whitney tests, p<.05). Self-reported visual function was significantly (p <.05) more correlated with standardised performance than with compensated function for the pouring (2-tailed Spearman’s r=0.66 vs. 0.42) and key tasks (r=0.76 vs. 0.62), whereas reported function in the food task was similarly correlated with each (r=0.45 vs. 0.41). Visual acuity (VA) was also better related to observed standardised task performance than to compensated function.
Conclusions: :
The results suggest that in certain ADL the visually impaired tend to derive self-evaluations of performance as if the tasks are performed in a conventional (standardised) way, which is a better reflection of their severity of vision loss (VA), despite instructions to report habitual (compensated) function. Such effects appear greatest for tasks in which there is a greater potential to employ compensatory strategies. Assessing the results of rehabilitation in ADL may be better served by using objective assessments rather than self-report.
Keywords: low vision • macula/fovea • quality of life