Prevalence and sociodemographic factors associated with vision difficulties in Ghana, Gambia, and Togo: a multi-country analysis of recent multiple Indicator cluster surveys

The global community has made significant efforts in reducing vision problems. In 1999, the World Health Organization (WHO) and the International Agency for the Prevention of Blindness initiated “Vision 2020: The Right to Sight” that aimed to eliminate avoidable blindness [1]. Also, the WHO adopted the 2014–2019 Global Action Plan dubbed ‘Universal Eye Health’ in 2013 [2]. This action plan was underpinned by principles and approaches such as universal access and equity, human rights, evidence-based practice, a life course approach, and empowerment of people with vision impairments (VIs) [2]. The action plan aimed to reduce the prevalence of avoidable VIs by 25% from 2010 to 2019 towards securing access to rehabilitation services for people with VIs [2, 3]. Nevertheless, VIs is a major global public health burden [4]. In this context, the term ‘vision impairment’ includes moderate and severe VIs as well as blindness [2]. According to the WHO, about one billion people globally have some level of VIs, mostly with near or distance vision [5]. Specifically, over 36 million people are blind and another 217 million live with moderate or severe VIs [6]. About 90% of the world’s visually impaired live in low-and middle-income countries (LMICs) [2], where the delivery of ophthalmic services is undermined by the scarcity of infrastructure, shortage of human resources and high user fees [6]. Nonetheless, about 80% of all VIs are largely preventable or treatable with minimal interventions [7]. VIs affect economic and educational opportunities, reduce quality of life, and increase the risk of death [3, 8].

As major causes of significant morbidity, VIs are largely attributable to refractive error, cataract, glaucoma, corneal opacities, diabetic retinopathy, trachoma, and presbyopia amongst others [3, 5]. The risk factors include diabetes mellitus, smoking, premature birth, rubella, and vitamin A deficiency [2]. With over 600 million people projected to be living with diabetes by 2040 [9], the number of people with diabetic retinopathy and resulting VIs is expected to rapidly rise, particularly among the economically active younger age groups in regions including sub-Saharan Africa (SSA) [1, 10, 11]. Age, gender (sex), nutritional factors among others are significant risk factors of VIs [12]. About 84% of people with VIs are aged 50 years and above as well as live in poor conditions. The female gender has been a significant predictor of VIs and a barrier to eye care services, with about two-thirds of all blind people globally being the poorest and oldest females. There is high prevalence and unfavourable odds of vision problems among women compared to their male counterparts [1, 13‐17]. This required more concerted efforts to improve eye health, especially among females, thereby highlighting the global attention to dub the 2009 World Sight Day as ‘Gender and eye health: equal access to care’ [15]. With the rising sociodemographic status and life expectancy globally, there is a shift in the disease burden towards non-communicable diseases and disabilities including VIs [1]. Therefore, there was the need to include eye health in non-communicable and communicable disease frameworks to contribute to global initiatives that address ageing, marginalized and vulnerable groups [2]. This informed WHO’s adoption of the health system approach in its 2014–2019 Global Action Plan, which integrated eye care programmes into the wider health care system at all primary, secondary, and tertiary levels [2]. This sought to address the issue of access and cost for eye health care, as affected by social deprivation, using multisectoral preventive interventions [18]. In line with this, the Ghana’s National Health Insurance System [NHIS], for example, covered most ocular diseases, and almost every district has an ophthalmic nurse, as well as a very active private eye care sector [19, 20].

The sociodemographic, economic and contextual factors and the resultant socioeconomic position of individuals that influence vision functioning and the development of VIs underline the social determinants of health (SDOH) framework [21, 22]. The SDOH framework explains how structural differences in income, education, occupation, gender (sex), social class, and race/ethnicity amongst others influence health outcomes in populations [21, 22]. These structural mechanisms affect a wide range of health, functioning, and quality-of-life outcomes and invariably determine people’s exposure and vulnerability to health-compromising conditions [21]. In tandem with the 2014–2019 Global Action Plan, the SDOH framework conceptualize the health system itself within the context of SDOH and seek improved health systems and delivery to reduce VIs [21]. With about 90% of the world’s visually impaired living in LMICs such as Ghana, Gambia, and Togo [2], there is a need for the application of the SDOH framework and health equity approach [23]. To the best of our knowledge, there is a paucity of literature that used nationally representative data to explore the prevalence and predictors associated with vision difficulties in multiple countries in West Africa. Additionally, WHO’s 2014–2019 Global Action Plan stipulated the need for cutting-edge research in developing new and more cost-effective interventions, especially those that are applicable in LMICs [2]. By using the SODH framework, this study aimed to explore the gender disparity in the prevalence and sociodemographic factors associated with vision difficulty (a proxy for vision impairment) in persons aged 18–49 years living in Ghana, Gambia, and Togo by performing a multi-country analysis of recent Multiple Indicator Cluster Surveys (MICS).

The sense of sight is one of the important human functions given that is required for independent functioning and survival. We report on the gender disparities in the prevalence and sociodemographic predictors of vision difficulties in three countries in West Africa namely Ghana, Gambia, and Togo. The prevalence of vision difficulties in males was 14.67%, 11.64% and 14.86% for Ghana, Gambia, and Togo, respectively. The prevalence of vision difficulties among females was 19.12%, 9.76%, and 23.61%, respectively. This highlights variations in the burden of vision difficulties in both males and females across the three countries under review, with females in Ghana and Togo recording higher prevalence. On the contrary, the burden of vision difficulties was lower in the female participants of The Gambia relative to the burden in the males. Gender inequalities in vision difficulties to the disadvantage of women have been reported in the literature [14]. These gender differences have been attributed to factors such as gender inequalities in access to health care as well as infrequent and ineffective use of health care services due to gender socialization [13, 14].

Consistently, people aged 40 years and above in all the three countries had a significantly higher likelihood of having vision difficulties as compared to their counterparts below 20 years. This finding was consistent in all the female participants in Ghana, Gambia and Togo as well as all the male participants in Ghana and Gambia except Togo. Literature suggests that as people age, the anatomy and physiology of the eye changes [33]. This is likely to be the case for the observations we made in this present study. Although, the cause of vision loss is multifactorial and cannot be attributable to ageing alone, it appears that ageing is a leading factor. This finding is consistent with previous studies that reported a higher likelihood of vision difficulties with ageing [34‐36]. Age-related changes in the anatomy and physiology of the eye, therefore, largely explain the observation that people aged 40 years and above had a higher likelihood of vision difficulties.

Educational level was found to be a significant predictor of vision difficulties in only Ghana and Gambia among the female sub-samples. In Ghana, it was observed that relative to people with higher education, those with Junior and Senior Secondary School (JSS and SSS) education had higher likelihoods of having vision difficulties. The result is consistent with a previous study that also reported that relative to those with a university education, individuals with lower educational attainments had a higher likelihood of vision difficulties [34]. Another systematic review reported that educational attainment was inversely associated with vision difficulties [37]. Higher educational attainment provides greater knowledge and access to healthcare resources and practices which are important for improved health including better eyesight [38, 39]. Participants with lower educational level may therefore not be benefitting from these resources. However, it was observed in The Gambia that relative to females with Junior High School education, those with Primary or no-education had decreased likelihood of vision difficulties. Nevertheless, it is difficult to be conclusive about the direction of the observed association as vision difficulty itself can also affect academic attainment [40].

Household wealth status was found to be significantly associated with vision difficulties among only the male participants in Ghana. We found that relative to males from households in the richest wealth quantile, their counterparts from middle wealth quintiles were associated with higher odds of vision difficulties. Our explanation for this observation may be related to the fact that individuals from the richest households are perhaps able to afford the cost of early diagnosis and treatment for eye conditions which results in a low burden of vision difficulties. Our findings corroborate the results of other reviews which also reported that income status was inversely associated with vision difficulties [37]. Governments of these three countries should develop pro-poor policies to help improve the financial status of their populations and its associated benefits on health including vision care.

Our findings also revealed a decreased likelihood of vision difficulties among Gambian and Togolese females who were currently in marriage compared to their counterparts who were never married. On the contrary, we found that Togolese males who were formerly married had a higher likelihood of having vision difficulties compared to those who were never married. Zheng et al. [41] reported that having unmarried status is associated with an increased risk of vision difficulty [41]. One plausible explanation is that marital status provides economic and emotional support for early treatment of vision difficulties. Moreover, the lack of support for self-care and social isolation may partly explain the high burden of vision difficulties among those with unmarried status, especially in the elderly populations [41, 42]. Therefore, couple-friendly services may be considered in increasing the uptake of vision care services.

The study also revealed some regional and sub-national variations in the burden of vision difficulties across Ghana, Gambia, and Togo in both the male and female participants. This calls for further research to explain the contextual factors explaining the intra-regional variations in the burden of visual difficulties. From a policy standpoint, our findings highlight substantial burdens of vision difficulties in Ghana, Gambia, and Togo. There is a need for health interventions that address the vision care needs of older individuals. Our findings also highlight the need to support individuals who were formerly in marriage, especially among older males to encourage the early treatment of vision difficulties. The observed gendered differences in how age, education level, marital status, and region of residence associate with reported vision difficulties also underscores the need to address the existing gender inequities that affect vision difficulties and other health outcomes.

The study revealed gender differences in the burden of vision difficulties in Ghana, Gambia, and Togo. There were also observable gender differences in how age, educational level, marital status, and region of residence were associated with reported vision difficulties. The findings imply the need to tackle the existing gender inequities that affect visual difficulties to promote the quality of life of individuals, especially the elderly.