Creation and testing of a practical visual function assessment for use in Africa: correlation with visual acuity, contrast sensitivity, and near vision in Malawian adults

Aim-To develop and test a practical visual function assessment for use in d eveloping countries. Methods-Using focus group discussions and interviews with eyecare workers a nd low vision specialists in Malawi, 13 questions related to visual charact eristics of activities of daily living were designed. Patients presenting t o an eye clinic were recruited and interviewed. Visual acuity, near vision, and contrast sensitivity were measured. Analysis sought: to determine the degree of correlation between the vision indices and visual function. Results-The visual function questionnaire was easy to administer. Visual fu nction correlated with visual acuity, contrast sensitivity, near vision, an d patient reported visual problem. People with a higher frequency of "not a pplicable" responses had lower visual function scores. Multivariate modelli ng revealed that visual acuity and number of questions felt to be applicabl e were independently associated with visual function. Reducing the question naire to nine questions did not affect the degree of correlation with any o f the visual indices. Conclusion-The authors' visual function assessment correlates well with dif ferent measures of visual acuity, People with reduced vision for a prolonge d period may no longer consider doing certain tasks and the number of quest ions considered appropriate by an individual may be an additional measure o f visual function. Assessment of visual function by health workers may be a valuable tool in improving surgical uptake by encouraging both health pers onnel and patients to recognise that they have difficulties undertaking act ivities of daily living as well as a measure of monitoring and evaluating c ataract outcomes.