Factors that influence eye care utilization in Nigeria: a systematic review

Abstract

Purpose

Various factors have been identified to influence eye care utilization in Nigeria, but no study has synthesized evidence from primary research on factors that influence eye care utilization in Nigeria. This systematic review was conducted to synthesize evidence from primary studies on determinants of eye care utilization in Nigeria.

Methodology

We searched peer-reviewed journals from three databases for studies that investigated drivers of eye health service uptake in Nigeria. The retrieved articles were screened based on clearly defined eligibility criteria. The selected articles were appraised for quality using the Joanna Briggs Institute (JBI) for quantitative and qualitative studies and Mixed Methods Appraisal Tool (MMAT) for mixed-methods studies. The review utilized mixed-methods approach and included quantitative and qualitative papers that met the eligibility criteria were selected.

Results

In all, 18 articles satisfied the eligibility criteria and were included in the analysis. The factors that influenced eye care utilization in the studies were cost of services, lack of eye care services, knowledge and attitude towards available services, proximity to eye care service centres, cultural and religious biases towards eye care services, having individual or family history of eye problems. Across all articles, cost of services was reported as a key barrier to utilization of eye care services in Nigeria. This is modified by social economic factors such as level of education and age of patients.

Conclusion

Addressing the factors that influence eye care utilization in Nigeria will improve eye care utilization and may reduce the burden of preventable blindness in Nigeria. This will enhance the World Health Organization (WHO) global strategic plan to enhance eye care services to the underserved populations.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-026-26630-y.

Introduction

An estimated 2.2 billion people worldwide have vision impairment and almost half of these cases are due to preventable causes [1]. A significant proportion of this number live in low income countries including Nigeria [2]. In Nigeria, approximately 4.8 million people are blind, while about 1.2 million suffer from severe vision impairment [3]. This is compounded by lack of awareness of eye care services, financial constraints, cultural beliefs, poor infrastructure, disparity in accessible eye care services and other socio-economic factors [4]. About half of the global population is projected to have various degrees of vision impairment by 2050 due to barriers like inadequate access to eye care services, increase in population and aging, with low and middle income countries (LMICs) bearing more burden of vision impairment [5].

Vision 2020: Right to Sight primarily focused on improving access to quality eye care and reducing inequalities in service delivery [6]. Building on this foundation, “2030 In Sight” represents a renewed global direction for eye health, emphasizing a system-wide integration of eye care within primary healthcare [7]. One of the central aims of “2030 In Sight” is to improve the use of eye care services by addressing barriers that limit access.⁷ Within this global framework, eye care delivery spans multiple levels of the health system. At the community and primary healthcare levels, services typically include eye health education, basic screening, and referral, while secondary and tertiary levels provide more specialized services such as cataract surgery, glaucoma management, and rehabilitative care. Functional referral pathways across these levels are therefore critical for timely access to specialized eye care [8].

Consistent with these global priorities, Nigeria has introduced measures to expand access to eye care, including the integration of eye care services into primary healthcare, as outlined in the National Eye Health Strategic Plan (2018–2022).⁸ These efforts aim to bring eye care closer to communities, support earlier detection of eye conditions, and strengthen referral to higher levels of care when required. However, progress has been uneven, with persistent challenges such as limited resources and weak referral systems continuing to restrict access to specialized services. The World Vision Report also recognizes the delivery of eye care through primary healthcare platforms as an effective approach to improving access to quality eye care services [9].

The goal of incorporating eye care within the primary healthcare service delivery is to ensure that patients can access eye care as part of comprehensive healthcare services [10]. Primary eye care covers important elements such as affordability, accessibility, availability and sustainability, and these components of eye care influence service uptake [11].

Despite the progress made in enhancing access to eye care, available evidence suggests that eye health remains under-utilized in Nigeria, with marked geographical disparities in service reach and uptake in urban and rural settings in the country [12]. Although Nigeria has formally committed to expanding equitable health coverage through its National Health Policy (2016) and articulated goals for eye health integration in the National Eye Health Strategic Plan (2019–2023), eye care services remain underfunded and inadequately integrated into the broader health system. This gap suggests that core components of universal eye health including availability, affordability, and accessibility are constrained in practice.

This gap between international commitments and local implementation underscores the persistent underutilization of eye care services in Nigeria, highlighting systemic barriers that hinder progress toward universal eye health. While relevant policies and strategic frameworks are in place, their impact at the population level remains limited, as many Nigerians continue to face systemic barriers that restrict their ability to access and utilize eye care¹³.

Recent studies have identified several factors that drive service uptake among Nigerian adults. These include financial burden related to eye care access, knowledge and attitude towards available services, distance from service delivery points, cultural and religious biases towards eye care services and having individual or family history of eye problems [4, 12, 13]. Even when eye care services are available, less than one-quarter of the population utilize the services because of barriers such as lack of awareness, cost of services, distance to access the services, cultural and religious biases [14].; [15]

Although the studies covered various demographics of adult population including urban and rural areas, the studies are region-specific, and the findings may not be generalizable. In addition, utilization patterns appear to be context-specific due to local health beliefs. There is no comprehensive synthesis of the evidence from the studies conducted to investigate the uptake of eye care in Nigeria.

The purpose of this review is to synthesize primary evidence on factors that influence eye care utilization in Nigeria. In this study, eye care utilization is conceptualized as seeking eye health for various purposes including promotion, prevention, clinical management and rehabilitation of eye health conditions [16]. Operationally, eye care utilization denotes timely and appropriate uptake of available services including routine eye care and specialized services such as surgeries and rehabilitative services [17]. In this review, eye care utilization is extended to eye care decisions taken by parents or caregivers on behalf of their children or wards.

Eye care utilization is central to achieving universal eye health (UEH), which is an important component of WHO’s broader universal health coverage agenda. Thus, addressing the factors that influence utilization of eye health in Nigeria may lessen the impact of preventable blindness in Nigeria. The outcome of this systematic review may be useful to inform policy and guide service delivery strategies. In addition, the understanding of determinants that shape eye care use in Nigeria will support the development of targeted interventions to improve service uptake and reduce preventable blindness in the country [18].

Materials and methods

Study design

This review adopted the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) approach [19]. The PRISMA guidelines were applied to guide the identification, synthesize and analysis of evidence related to determinants of eye care utilization in Nigeria. In addition, the review protocol was prospectively registered on PROSPERO (CRD42024622935).

Search strategy

A preliminary search was done in selected electronic databases such as PubMed and Google Scholar based on the title of the review. We conducted comprehensive searches in selected databases, PubMed, Web of Science, and Scopus from January 10 to February 11, 2025, for relevant articles published in English between January 1, 2014, and February 11, 2025. Key terms in the review title were used to develop search strategy and were modified with Medical Subject Headings (MeSH) to ensure all relevant articles were included in the review. The key words related to Boolean operators “AND” and “OR” to retrieve all relevant articles. In addition, the reference lists of the selected articles were manually reviewed to ensure relevant articles were not omitted in the review. The key words were combined in the format: (((Nigeria) AND (“Eye care”)) AND (utilization OR uptake OR barrier)) AND (factor OR determinant). Identical search strategy was used in each database to ensure methodological consistency and reproducibility. Two independent authors (MA and GW) conducted the search, and the results were compared for similarity and discussed amongst the four authors (MA, GW, AD and EB) in a virtual meeting.

Screening and extraction of studies

This process was done using the Covidence where the search results were uploaded by one author (GW). Three co-authors, MA, GW and AD independently screened the articles and discrepancies were resolved in a discussion with the fourth author, EB who is an expert in the subject. Title and abstract screening were conducted by three authors, MA, GW and AD separately and conflicts were resolved in a meeting with the fourth author, EB. Then the full texts of the articles were retrieved by one author, GW and saved in Covidence for full texts screening. The full texts of the articles were screened by three authors MA, GW and AD independently and discrepancies were addressed in a meeting with the fourth author, EB. In each of the stages, consensus was achieved by the four authors. The screened articles were extracted and saved automatically in Covidence and back up retrieved and saved in Excel by the lead author, MA.

Inclusion and exclusion criteria

In this study, eye care utilization is defined as seeking eye care services for various purposes including promotion, prevention, clinical management and rehabilitation of eye conditions. Thus, we included studies that are focused on various aspects and levels of eye care seeking behaviour or habits. Studies that investigated uptake of eye care services including outreach programmes and surgical services were considered. The study was focused on adult Nigerians 18 years and above. Therefore, all studies that involved utilization of eye care services by adult Nigerians or those involving parental or caregiver decision for eye care utilization of children were also included. The factors of eye care utilization were extended to include awareness of available care options and determinants of eye care utilization. Primary research evidence including those that explored quantitative, qualitative and mixed methods approaches were considered for inclusion if they were published in English between January 1, 2014, and February 11, 2025.

However, review studies were excluded as they did not provide primary data [20]. Similarly, commentaries, expert opinions and editorials were not considered because they provide low quality evidence [21].

Quality assessment

In this review, we appraised the quality of the studies using Joanna Briggs Institute (JBI) and Mixed Methods Appraisal Tool (MMAT) which are validated tools [22]. The selection of the tools was based on previous similar reviews on eye care utilization in other populations [23–25].

Out of the 18 studies included in the review, 10 studies were quantitative studies, 6 studies were qualitative studies while 2 studies were mixed-methods studies respectively.

Using the validated tools, 18 eligible articles were appraised independently by MA and GW, and any discrepancies were resolved through discussion with the other reviewers (AD and EB). For quantitative studies, eight criteria were assessed using the JBI checklist:

1. were the criteria for inclusion in the sample clearly defined?

2. were the study subjects and the setting described in detail?

3. was the exposure measured in a valid and reliable manner?

4. were objective and standard criteria used for measurement of the condition?

5. were confounding factors identified?

6. were strategies to deal with confounding factors addressed?

7. were the outcomes measured in a valid and reliable way? 8) was appropriate statistical analysis used?

Similarly, the checklist for the qualitative studies included in the review consisted of nine (9) questions as follows:

1. Is there congruity between the stated philosophical perspective and the research methodology?

2. Is there congruity between the research methodology and the research question or objective

3. Is there congruity between the research methodology and the methods used to collect data?

4. Is there congruity between the research methodology and the representation and analysis of data?

5. Is there congruity between the research methodology and the interpretation of data?

6. Is there a statement locating the researcher culturally or theoretically?

7. Is the influence of the researcher on the research, and vice versa addressed?

8. Are participants, and their voices adequately represented?

9. Is the research ethical according to current criteria, or for recent studies, and is there evidence of ethical approval by an appropriate body?

Furthermore, five (5) questions were used in the checklist for mixed-methods studies using MMAT appraisal tool.

1. Is there an adequate rationale for using a mixed-methods design to address the research question?

2. Are the different components of the study effectively integrated to answer the research question?

3. Are the outputs of the integration of qualitative and quantitative components adequately interpreted?

4. Are divergencies and inconsistencies between quantitative and qualitative results adequately addressed?

5. Do the different components of the study adhere to the quality criteria of each tradition of the methods involved?

A simple scoring system was used for the JBI and MMAT. A score of zero (0) was assigned to a “no” or unclear answer while a score of one (1) was assigned to a “yes” answer. Each study was graded on a total score of 8, 9 and 5 for qualitative, quantitative and mixed- methods studies respectively. The total scores were calculated and expressed as a percentage of total scores. In line with similar reviews, a score of less than 60% was considered low quality, a score of 60% to 79% was considered average quality while a score of 80% and above was considered high quality of evidence [24].

Data extraction

We relied on similar previous systematic reviews in extracting relevant data for synthesis and analysis in the review [23–25]. We collected data on key attributes of the articles including author, publication year, title of article, aim of study, setting or state and region of Nigeria where study was conducted, study design, sampling method, sample size, data collection, data analysis, demographic data including age, male to female ratio and determinants of eye care utilization in Nigeria were extracted and presented under summary of findings. Both quantitative and descriptive data on eye care services were extracted and saved in an Excel sheet. The data extraction was conducted by three independent authors (MA, GW and AD) using the Covidence and conflicts were addressed in a discussion with the fourth author (EB).

Data analysis and synthesis

The characteristics of the articles selected were summarized as a table. This includes summary of demographic data and key findings of the articles. The main analysis was conducted on determinants of eye care utilization in Nigeria. First, we conducted thematic analysis on qualitative data including demographic data, financial barriers, geographical access challenges, poor awareness, cultural and religious factors. Since the population is heterogenous, we conducted sub-group analyses to explore various factors of eye care utilization. We also conducted subgroup analyses on geographical location, to explore influence of geographical location (urban and rural) on uptake of eye health.

Results

Result and analysis

For this study, three databases were searched, yielding a total of 82 research articles. Of these, 45 articles were retrieved from PubMed, 19 from Web of Science, and 18 from Scopus. Subsequently, 31 duplicate references were automatically identified and removed by Covidence. As a result, 51 studies were screened against the aim and objectives of the review, and these were assessed for full text. Following a critical full-text evaluation, 25 studies were excluded, leaving 26 studies for eligibility assessment. During this stage, 8 articles were removed because of incorrect outcome (n = 1), incorrect intervention (n = 1), unavailability of full text (n = 1), inappropriate age group (n = 3), and publication date prior to January 2010 (n = 2). Ultimately, 18 articles met the eligibility criteria, as illustrated in Fig. 1, which is a PRISMA flow diagram.

Fig. 1.

PRISMA flow diagram showing the process of study identification, screening, eligibility assessment and inclusion in the review

Overview of articles and table of characteristics

As stated above,18 eligible articles, representing empirical studies conducted at different locations in Nigeria to examine determinants of utilization of eye health, were retained for final analysis. The review included qualitative (n = 6; semi-structured interview and focus group discussion n = 3, semi-structured interview only n = 1, questionnaire n = 2), quantitative (n = 10; survey form = 2, questionnaire = 6, GIS-based articles (n = 2), and mixed methods (n = 2, questionnaire n = 1, semi-structured interview n = 1).

Across the 18 articles analyzed, sample sizes ranged from 27 to 3,926 participants. The studies were conducted across multiple states spanning Nigeria’s six geopolitical zones. The South-East zone accounted for the highest number of studies (n = 7), conducted in Enugu (n = 3) and Anambra (n = 4). Two (2) studies were conducted in South-West zone (Oyo = 2) while two (2) studies were conducted in South-South zone (Cross Rivers = 1; Edo = 1). Seven (7) studies were conducted across northern zones, including the North-Central (Kwara = 1; Kogi = 1), North-West (Zamfara = 1, Jigawa = 1, Kano = 1, Katsina = 1) and one (1) study was conducted across two settings (Kaduna and Abuja). No study was conducted in North-East zone. A summary of the geographical distribution, study designs, and data collection methods of the included articles is presented in Table 1.

Table 1.

Distribution of key features of the 18 articles included in this study

Lead author and year of publication	State	Study type	Method of data collection
Olokoba et al. 2016 [37]	Kwara	Quantitative	Survey form
Penzin et al. 2024 [38]	Kogi	Quantitative	Remote sensing, GPS
Kyari et al. 2016 [26]	Abuja and Kaduna	Qualitative	Focus Group discussions, In-depth interviews, and Direct observation
Okoye et al. 2018 [28]	Anambra	Qualitative	Semi-structured interviews
Kizor-Akaraiwe, 2019 [40]	Enugu	Quantitative	Questionnaires administered through phone interviews
Eze et al. 2016 [4]	Enugu	Qualitative	Questionnaire
Umar et al. 2015 [39]	Zamfara	Quantitative	Structured population-based survey
Olawoye et al. 2023 [31]	Oyo	Quantitative	Semi-structured Questionnaire
Ezinne et al. 2023 [12]	Enugu	Quantitative	Structured Questionnaire
Onwubiko et al. 2014 [27]	Anambra	Quantitative	Questionnaire
Tafida & Gilbert, 2016 [35]	Jigawa	Mixed	Semi-structured interviews
Olusanya et al. 2016 [32]	Oyo	Quantitative	Structured questionnaire
Okolo et al. 2024 [33]	Kano	Quantitative	Questionnaire
Arinze et al. 2015 [36]	Anambra	Mixed	Questionnaire
Lohfeld et al. 2021 [29]	Cross Rivers	Qualitative	Focus Groups Discussions, Semi-Structured Interview,
Onwubiko et al. 2015 [30]	Anambra	Qualitative	Questionnaires
Ebeigbe, 2018 [13]	Edo	Qualitative	Focus Groups Discussions, Semi-Structured Interview,
Taryam et al. 2020 [34]	Katsina	Quantitative	mRAAB Android-based software

Quality assessment of included studies

Using the quality appraisal tools described above (JBI and MMAT), the methodological quality of the included studies ranged from moderate to high score. Only three of the eighteen studies, all employing qualitative designs achieved a perfect quality assessment score of 10/10. Nine (9) studies (2 qualitative and 7 quantitative) attained scores of 8/10, indicating good methodological quality. The remaining studies scored between 5/10 and 6/10, reflecting moderate quality. Overall, while most studies met key quality criteria, variation in methodological rigor was observed across study designs (Fig. 2).

Fig. 2.

Quality assessment scores of eye care utilization studies in Nigeria

The qualitative studies have a maximum quality score of 10/10, with three demonstrating strong methodological rigor [26–28]. Two qualitative studies show methodological limitations related to researcher positioning and reporting of ethical considerations [29, 30]. The quantitative studies have a maximum score of 8. The most recent studies (2023–2024) show stronger methodological quality while older studies (2015–2016) often lack strategies for confounding factors, reducing their reliability. Mixed-methods studies have a maximum score of 5. Both mixed methods of studies have excellent scores (5/5), showing effective integration and interpretation of diverse data sources that meet the criteria of this systematic review.

Critical appraisal of articles included in this review identified several studies as demonstrating high methodological quality [26, 28, 31–38].. According to the critical appraisal tools, the common weaknesses of the average and low-quality papers were lack of attention to confounding factors especially in the quantitative papers, and insufficient researcher positioning in some qualitative studies (see Fig. 2 for quality assessment).

The evaluation is based on the total scores derived from the structured quality assessment framework as described above and represented in Fig. 2.

Figure 2 visualizes the total quality scores of each study. It highlights the methodological rigor and completeness of each study type. Qualitative studies generally scored out of 10, quantitative studies out of 8, and mixed methods studies out of 5.

An overview of the participants’ characteristics showed wide variation in age, gender, education and occupation. The distribution of the studies across the six geopolitical zones of the country has also been considered. This was used to evaluate the nature of the outcome of each study with regards to the reason for eye care utilization in relation to the socioeconomic status of each state in the country.

Thematic analysis of factors that influence eye care utilization in Nigeria

Using the data provided in this study, barriers to eye care utilization in Nigeria represent a multifaceted challenge, with economic, informational, infrastructural, cultural, and perceptual factors intersecting to limit access to timely and appropriate services. Across the 18-literature adopted, these constraints are evident in both rural and urban contexts, though they manifest more acutely in underserved areas, particularly rural and hard to reach communities.

Financial constraint

This marked the dominant factor that constrained eye care utilization in Nigeria, which consistently emerges as a major deterrent to accessing eye care. In Kwara State [37] high cost of surgery was identified as a key barrier, while in Kogi State [38] cost of services was reported to significantly discourage uptake. Similar findings were reported in Zamfara State [41], in which lack of money was linked to non-utilization, and in Ibadan, Oyo State [31] in which both the cost of transportation and poor income were cited as limiting factors. In Enugu State [33], in which long distance by patients compounds the expense of eye care while in Jigawa State [37], high costs of eye care services were identified as a driver of reliance on couching, a traditional cataract treatment, instead of professional eye care services.

Knowledge and awareness gaps

This factor also constitutes a significant barrier to utilization. Reports from Abuja and Kaduna State [26], revealed that lack of awareness about glaucoma and absence of informed treatment choices reduced care-seeking behaviour. In Anambra State [28], low awareness of glaucoma was found, which is a trend mirrored in Kano State in which [33] poor knowledge of available services was identified. While in Enugu State [4] many patients could not distinguish between optometrists and ophthalmologists, a knowledge gap shaped by socio-demographic factors. Misconceptions about the nature of eye diseases were also reported; in Anambra [27], in which some individuals attributed vision loss to ageing and believed it could not be cured.

Geographical and infrastructural barriers

Access to eye care services was limited by both geographical distance and infrastructural barriers, particularly among rural populations. In Enugu State [33, 42], long distances to service points and poor road networks were highlighted as barriers to eye care utilization. While in Anambra State [28], the concentration of services in urban centres disadvantaged rural dwellers. Similar challenges were identified in Oyo State [31] and Jigawa State [35], in which the absence of proximate services forced patients to undertake burdensome travel.

Cultural beliefs and preference for alternative care

Cultural beliefs and preference for alternative care emerged as important factors influencing eye care utilization, often driven by limited trust in conventional eye care services and perceptions of greater effectiveness of traditional or informal alternatives. In Anambra State [31], the use of spiritual interventions and harmful traditional eye medications were documented, which are driven by distrust of conventional eye care services and perceptions that traditional approaches offer quicker relief, while in Jigawa State [35] the perceived responsiveness and immediate visual improvement offered by couchers attracted patients to consider unconventional eye care practice. In Benin [11], the continued reliance on self-assessment of need and harmful traditional remedies were noted, which was underpinned by distrust of formal systems.

Fear, perception, and attitudinal factors

This factor also features prominently in the data collected in this systematic review study. In Kwara State [39], reported fear of losing sight after surgery as a deterrent, while in Kogi State [40], identified fear of treatment outcomes and lack of confidence in services. In Katsina State [36], found that lack of felt need, combined with the cost of services, led to non-utilization. Poor experiences with healthcare providers, including discourteous behaviour, were noted in Enugu State [40], which further erodes trust in formal eye health services and discouraged timely utilization of services.

Social and logistical support limitations

This factor typically influences eye care utilization. In Kwara [39], absence of escorts was cited as a reason for not seeking care, a theme observed in Abuja and Kaduna in which [26] weak family support structures was reported. In Cross River State [30], family disagreements, lost referral letters, and inability to take time off work impeded attendance at follow-up appointments.

Critically, when the factors are evaluated together, the literature demonstrates that although barriers to eye care utilization in Nigeria are multifaceted, the cost of accessing services, encompassing both direct medical expenses and indirect costs such as transport, emerges as the most implicating factor. Across diverse states and populations, financial limitations consistently intersect with other barriers, amplifying their effects and resulting in delayed or lack of treatment. Addressing this central economic challenge is therefore critical to improving equitable access to eye care nationwide.

Discussion

The purpose of this review was to evaluate evidence from primary studies that investigated factors of eye care utilization among Nigerian population. In total, we identified 18 studies that met the eligibility criteria. This review included studies from 13 States in Nigeria, in addition to the Federal Capital Territory.

Our review demonstrates that various interrelated factors influence eye care utilization in Nigeria. These factors range from financial difficulty, poor knowledge and lack of awareness of eye care services, poor road infrastructure, cultural biases, perception and fear of unfavorable outcomes of eye care services, and lack of family support.

Evidence from this review highlights considerable variations in factors of eye care utilization across different studies. Predominantly, studies conducted in rural areas demonstrate cultural biases, financial constraints, and limited awareness of eye care services, whereas higher levels of awareness were observed among study participants from urban settings. One plausible explanation for the variations in the findings from these studies is the setting. While majority of the studies sampled participants from rural communities, which are associated with low income [27, 28, 30, 31, 33, 34, 36–38, 40, 41], others recruited participants from urban and semi-urban cities which may have higher income [4, 11, 26, 31, 33, 37, 40]. In addition, the variation in participants’ educational and occupational backgrounds may have contributed to the differences observed across studies.

Although participants in the review represented diverse sociodemographic backgrounds, the studies were limited by methodological issues. Two studies [11, 29] in our review obtained data from caregivers and parents rather than eye care service users (clients). The perspective of eye care utilization of the caregivers and parents may differ from the clients, and this may limit the generalizability of this review. Ideally data would have been obtained from the service users. However, this approach is also subject to recall bias as the participants may have difficulty remembering their experience with seeking eye care services [43, 44].

Across the 18 articles retained for final synthesis, the influence of socio-economic status of Nigerians on eye care service utilization is well acknowledged. Notably, financial constraints influenced the eye care-seeking behaviour of participants in the review. More than 13 studies identified financial constraints as the main reason for non-uptake of eye care services. When disaggregated, financial constraint as a factor of eye care utilization occurs in different forms including high cost of general eye care services [11, 12, 26, 27, 29, 36–39], high cost of specialized services such as eye surgical procedures [31, 34, 35, 40] and cost of transport to access eye care services [28, 33, 37, 42]. Even when eye care services are offered at subsidized rates or provided free of charge, the cost of transportation to the centres poses a constraint to accessing eye care services and may limit uptake of available services. Thus, indirect cost of transport to access eye care services compound financial constraints of Nigerians to uptake of services.

This outcome mimics the findings of related reviews that investigated determinants of eye care utilization in the sub-Saharan region [17, 23, 45]. Affordability issues and out-of-pocket payments for eye care services have been recognized as key determinants of eye care utilization in LMICs countries, particularly Nigeria [17]. This is largely due to lack of adequate insurance coverage for eye care services. Like most other countries in Sub-Sahara Africa (SSA), Nigeria healthcare services are not offered for free, and individuals cover the costs of services [17, 23, 45]. Thus, people delay accessing eye care services until eye or vision problems become severe. However, the studies in our review did not assess the financial implications of eye care services including costs of consultation, medication, surgery and transportation. This gap can be explored in future studies to strengthen evidence on cost-related barriers to eye care utilization in Nigeria.

This study also revealed the influence of geographical and infrastructural barriers to eye care utilization in Nigeria. Long distance to eye care centres and poor road infrastructure posed a major challenge to eye care uptake among the participants in the studies. Clients spend several hours to access eye care services because of poor road infrastructure as most health centres are in urban areas [30, 38, 41]. Absence of infrastructure further exacerbates the maldistribution of eye care health practitioners in rural communities [44]. This finding is well documented in many LMICs where poor eye health infrastructure limit availability and access to eye care services [23, 25]. Another possible reason for higher uptake of services among patients residing in the urban areas is the good access to the media and health information. Although, in recent time, there is progress in the integration of eye care into primary care services [7, 8, 45–47], but poor road network in rural communities hinders and delays clients from attending eye care health centres [10]. Thus, resulting to increased burden of preventable blindness and overall poor health outcomes [10, 48].

Even when eye care services are provided, awareness among the population remains limited. While some study participants demonstrated complete lack of awareness of eye care services, especially specialized services like glaucoma [26, 40], others erroneously believed that there was no cure for their eye conditions [28, 39, 41]. This may be associated with the socio-economic status of the rural dwellers who tend to have poor knowledge of general health care services [23, 25]. In addition, eye care services and personnel are inequitably distributed, having more resources in the urban and semi-urban cities of Nigeria, while the rural communities who have more needs for eye care services are underserved [8, 47, 49]. This maldistribution justifies the higher level of awareness of eye care services among the urban, educated and higher income groups [25, 43]. Variation in awareness of eye health care services has been robustly documented in literature [45]. In Kenya [50], rural and the underserved populations receive poor eye care services. Thus, contributing to the high burden of avoidable blindness in rural communities [51]. These findings reinforce the need to strengthen health care system by incorporating eye care services in the minimum service package for primary health care and, recruiting, training and or redeploying the existing eye health providers in Nigeria [52].

Reports have shown that patients’ knowledge of diseases is associated with higher utilization of eye care services [53, 54]. However, these studies are limited to Turkey and Chinese populations respectively. Besides, some chronic diseases, particularly diabetes, are characterized by progressive vision loss which may explain the increase in the utilization of eye care services among the affected patients. Contrarily, the studies in our review did not examine participants with diabetes with chronic complications, whose eye care seeking behaviour may differ from the general eye care patients because of increased disease burden associated with the former. Evidence from previous studies further supports this finding, indicating that chronic conditions are associated with uptake of health care services [55–57]. Although our review identified limited awareness as a major constraint to utilizing eye care services in Nigeria, poor awareness was not associated with the duration of disease.

Our study also found that cultural beliefs and preference for alternative care influenced eye care service utilization in Nigeria. Some participants preferred the use of traditional medicines such as herbal remedies and spiritual practices to seeking conventional medicines [27, 31, 37, 38]. Perhaps, the immediate symptomatic relief encountered by the participants fueled their confidence in the efficacy of readily available alternative options to address their eye health needs. This observation aligns with evidence from previous systematic reviews that explored determinants of eye care in LMICs. Cultural biases have been reported to influence uptake of eye health in LMICs where eye conditions are sometimes believed to be associated with witchcraft or punishment for wrongdoing [23, 25]. This leads to stigma and consequent avoidance of conventional eye care services. Instead, greater trust is placed on alternative means including spirituality [17].

This suggests that targeted health awareness campaigns are critical to addressing lack of knowledge and improving eye care utilization [25]. Although similar findings have reported preference to local alternatives to eye care services in LMICs, the current review demonstrates that this barrier is more pronounced in Nigeria. This may be due to strong cultural dimension in the Nigerian context. Misconception about eye conditions is believed to drive uptake of eye care services in LMICs where significant populations have mixed views of orthodox health care services.

Similarly, the perception and fear of unpleasant outcomes related to surgery and previous negative experiences of eye service users were found to influence how participants utilized eye care in Nigeria. Previous findings have been documented in other LMICs indicating that the perception of unpleasant outcomes of services is fueled by limited knowledge of disease severity, given that some threatening eye conditions may cause only subtle changes before significant vision loss [17]. However, this may be different in older adults with systemic conditions associated with eye problems [23].

Furthermore, in Nigeria, logistical and social factors impacted on the ability of participants to seek appropriate eye care services, and this limited the utilization of services even when available. Lack of family support hindered or delayed access to hospitals as family members are overwhelmed with economic demands. Evidence from literature suggests that older people have higher burden of visual impairment and mobility challenges [23].

Overall, this review demonstrates the influence of interplay of socioeconomic, cultural, infrastructural, demographic factors and other factors related to health systems, with socioeconomic factors having dominant influence in determining uptake of eye care services in Nigeria. Addressing the interrelated barriers will require multi-faceted approach including strengthening health care system, expanding coverage of eye care services in rural areas and developing targeted awareness programmes.

Strength and limitations

To the best of our knowledge, this is the first systematic review conducted to investigate the factors that influence eye care utilization in Nigeria. This review adhered to PRISMA reporting guidelines and was conducted using Covidence platform which enhanced the robustness and quality of the review. The use of Covidence added methodological rigor by streamlining the screening process and enhanced collaboration of the reviewers. The screening of the titles, abstracts and full texts of the articles was conducted independently by the reviewers, with each reviewer blinded to the decisions of other reviewers, as the process was carried out with the Covidence platform. This reduced bias during the screening and selection of eligible articles in the review. The elimination of manual tasks with Covidence also enhanced efficiency and tracking of progress in the review. However, the limitations of the review stem from restriction to articles published in English, and inability to conduct meta-analysis. To mitigate these limitations, we conducted quality assessment of the articles using validated tools and reported it transparently. In addition, we could not conduct meta-analysis because of the heterogeneity of the designs of the articles and the outcome of the studies. Although acknowledged as a potential limitation, restricting the articles to only those published within the last 10 years was to ensure relevance of evidence from the review as set in the eligibility criteria.

Conclusion

Our review highlights that multiple interrelated factors such as financial constraints, geographical and health system-related challenges influence uptake of eye care services in Nigeria. Among the factors, costs and affordability emerged prominently as major barriers to eye care service utilization in Nigeria. Addressing these barriers through practical policy measures, stronger health system, and more accessible service delivery may improve eye care service utilization in Nigeria and reduce the burden of avoidable blindness.

In practical terms, these findings underscore the need for measures that reduce the cost of eye care for patients, strengthen service delivery at the primary healthcare level, and improve referral pathways for specialized care. Future studies could build on this work by examining the costs associated with seeking eye care, assessing the effectiveness of interventions aimed at improving affordability, and exploring strategies to increase utilization in underserved communities.

Authors' contributions

MA conceptualized the study and registered the protocol with Prospero. MA and GW conducted the literature search. MA, GW and AD conducted the screening and selection of articles and conflicts were discussed robustly with EB. MA, AD and GW appraised the study quality and resolved conflicts with EB. MA and AD drafted the manuscript and all authors reviewed and approved the final version.

Funding

This study did not receive any funding from public, commercial or not-for-profit organizations. GW's role in this research is independent of his PhD research project, which is funded by the Legal & General Group, through a (research grant to establish the independent Advanced Care Research Centre at the University of Edinburgh. The funder had no role in the conduct of the study, interpretation, or the decision to submit for publication. The views expressed are those of the authors and not necessarily those of Legal & General Group

Data availability

Data extraction form is accessible from the corresponding author upon request.

Declarations

Ethics approval and consent to participate

This is not applicable. The study involved analysis of existing literature.

Consent for publication

This is not applicable.

Competing interests

The authors declare no competing interests.