Correctable visual impairment and its impact on quality of life in a marginalized Canadian neighbourhood

Objective: To study the impact of visual impairment due to either underlying ocular pathology or easily correctable refractive error on vision-related functioning and quality of life (QOL) in Vancouver's downtown eastside (VIDES). Design: Cross-sectional study. Participants: Two hundred consecutive patients seeking general medical care at the Vancouver Native Health Society (VNHS) medical clinic were included. Methods: An ocular examination was performed and a standardized history and QOL information were obtained for each participant. Effective visual impairment was classified based on patients' current refractive means. Pathological visual impairment was classified based on patients' best-corrected visual acuity (VA). Vision-related functioning was quantified using the Daily Tasks Dependent on Vision (DTDV) questionnaire. Health-related QOL was assessed using the 12-Item Short Form Health Survey (SF-12). Results: Two hundred patients participated; they suffered, on average, 6.2 comorbid conditions. Sixty-two patients (31%) were effectively visually impaired and, of these, 14 patients (7%) were effectively blind. Ten patients (5%) had pathological eye disease to explain their visual impairment. The remaining 52 visually impaired patients (26%) had VA that normalized with correction. Difficulty with the tasks described in the DTDV questions was significantly correlated with effective visual impairment. Patients with effective visual impairment had lower Physical Composite Scores on the SF-12 in multivariate analyses. Conclusions: We have demonstrated a very high rate of visual impairment in a low socioeconomic population that is associated with decreased vision-dependent functioning and decreased overall physical health status. Public health efforts need to be directed toward improving easily correctable refractive error.