Abstract
Background: The Universal Eye Health: A Global Eye Health Action Plan 2014-2019 aimed to reduce visual impairment (VI) as a global public health issue and improve access to rehabilitation services for the visually impaired. VI is associated with a reduction in the ability to perform daily activities, such as reading, writing, and recognising faces. Southern Africa, with a population of approximately 70 million (as per the latest United Nations estimate), includes five countries (including South Africa, with a population of 62 million) and has a VI prevalence rate of 2.11%, primarily due to uncorrected refractive errors (URE, 0.84%) and cataracts (0.59%). Lifestyle factors, malnutrition, body mass index (BMI), and stress levels are known to influence overall health, including eye health, which can impact quality of life, employment opportunities, and socioeconomic status. VI can also affect productivity and academic performance, with many cases being treatable.
Objective: This study aimed to investigate possible associations between lifestyle factors, malnutrition, BMI, and stress levels with VI and/or impairment of visual activity among University of Johannesburg students in South Africa.
Methods: A quantitative study was conducted using two standardised quantitative surveys. A total of 409 students aged 18 and older from any race or gender participated. Data on lifestyle factors (such as physical activity, dietary habits, and smoking), malnutrition indicators (dietary deficiencies and body composition), BMI, stress levels, and potential VI or impairments of visual activity (IVA) were collected via self-reported questionnaires, anthropometric measurements (height and weight), and visual activity assessments. The Lifestyle Appraisal Questionnaire (LAQ) was used to assess health risks and stress levels, with a total risk score (LAQ_TRS) calculated for each participant. The Visual Activities Questionnaire (VAQ), which includes self-assessment questions about vision, was used to assess visual impairment, producing a total score (VAQ_TS) for each participant. BMI was calculated based on weight and height measurements taken using a Casa electronic scale and Leicester stadiometer, respectively. Blood pressure (BP) was also measured using an automated sphygmomanometer (Model: TMB-1491-S). Univariate and multivariate statistical
analyses were conducted to explore relationships between variables, controlling for potential confounders.
Results: Since most variables were not normally distributed, non-parametric analyses were primarily applied. Measures of central tendency (means or medians) and dispersion (ranges, standard deviations, interquartile ranges, and quartile deviations) were mostly significantly different across genders, with some exceptions (age, diastolic BP, weight, LAQ_TRS, and colour discrimination). A weak but significant positive correlation (r = 0.27, p<0.05) was found between BMI and LAQ_TRS, while no correlation was found between BMI and VAQ_RS. Two new subscales are proposed for the LAQ: dietary disease risk (DDR) and stress event occurrence (SEO) in the six months preceding the study. Modest statistical associations were observed between DDR and LAQ_TRS, as well as DDR and VAQ_RS. Females scored higher median scores for both LAQ_TRS and VAQ_TS. Non-parametric Spearman correlations revealed associations between LAQ_TRS, VAQ_TS, and most variables of interest.
Conclusions: Lifestyle factors, dietary disease risk (potentially linked to malnutrition risk), and BMI appear to be associated with impairment of visual activity and/or VI. However, the association between stress levels (as a measure of recent stress levels) and impairment of visual activity was relatively weak.