Refractive Error and or Visual Impairment and Their Impact on Quality of Life Among School-age Children in Sub-saharan Africa; A Protocol of a Systematic Review

Refractive error (RE) is a leading cause of visual impairment (VI) in children, the most common cause of childhood handicaps, and the second leading cause of childhood blindness globally. Refractive error and/or VI limits the ability of a child to perform well at school, in most sporting activities which require good vision, and negatively affects the socio-economical security of an individual. These two conditions have also reported to impact quality of life (QoL). The epidemiological evidence about the prevalence and distribution of RE and VI, as well their impact on the QoL of school-going children in Sub-Saharan Africa (SSA), will assist policymakers and stakeholders involved in child eye care in channelling resources appropriately. The main objective of this scoping review study therefore is to map available evidence on RE and or VI and their impact on QoL of school-going children in SSA.

studies will be exported to a Mendeley library and in cases of outstanding articles the authors will be contacted directly. The title screening will be done by the principal investigator (PI), then the study will employ two independent reviewers which will have access to the Mendeley library to do abstract screening (AS) and a full article screening (FAS). Following FAS, data extraction will be done by PI. The quality index of all included studies will be determined using the Mixed Method Appraisal Tool (MMAT).
The results will be reported using the Preferred Reporting Items for systematic reviews and Meta-Analyses (PRISMA).

Discussion
The evidence of this scoping review will guide policy makers and all stakeholders in planning intervention strategies to address this global issue. Furthermore, the results of this review will be published in a peer reviewed journal and will be used to guide future research in this and related areas. (2) Refractive error is currently a leading cause of visual impairment (VI) in children, the most common cause of childhood handicaps, and the second leading cause of childhood blindness. (3,4) Refractive error and/or VI limits the ability of a child to perform well at school as it is known that 85% of learning depends on vision. Moreover, affected children cannot participate in most sporting activities which require good vision. The ultimate negative effect however is on the socio-economic security of affected individuals. (5) (6) Thus, not surprisingly, refractive error (RE) and or VI has been reported to impact the quality of life (QoL). (5) Furthermore, managing the impact of VI and blindness from uncorrected RE (URE) is costlier and puts more pressure on the global economy than managing RE itself. (7) Globally there are around 19 million visually impaired children (8) of which 12.8 million are due to uncorrected or inappropriately corrected RE with eight million children being classi ed as blind due to URE.(9) Ninety percent of children with VI were found to reside in the developing countries. (10,11) The impact of RE and VI onset before or during school-going age is signi cantly greater as compared to onset in adulthood, considering the greater number of years that they will likely carry these conditions in the case of the former.(1) The World Health Organization (WHO) developed a policy more than two decades ago in 1998 called the ''WHO global school initiative: Helping schools to became 'Health-Promoting Schools' '' and management of VI was included. (12) Two years later at the global meeting convened by the WHO in London, the recommendation that further information was required on the prevalence, incidence, and causes of VI among school-going children especially in the developing countries, emanated. (13) Further, in the initiation of 'VISION 20/20 RIGHT TO GOOD SIGHT' by the WHO and other non-government organizations (NGOs), the management of RE and VI in children was prioritized. (14) Knowledge of the magnitude and prevalence of RE and/or VI among school-going children therefore is vital for the proper channeling of resources for the management of these conditions. Moreover, it has been reported that RE and VI differ according to ethnic groups. (15,16) There is therefore a need for further research to be conducted to improve on the current knowledge and understanding of the epidemiology of these conditions which could facilitate future strategies to minimize the risks and manage it.
Epidemiological evidence about the prevalence and distribution of RE and VI, as well as their impact on the QoL of school-going children in Sub-Saharan Africa, will assist policymakers and stakeholders involved in child eye care in channeling resources appropriately. The objective of this scoping review study therefore is to map available evidence on RE and or VI and their impact on the QoL of school-age children in Sub-Sahara African (SSA).

Research question
What is the prevalence and distribution of RE and VI in school-age children in SSA, and the impact of these on their QoL? Methodology This review will map available evidence for SSA on RE and VI, as well as their impact on the QoL of school-age children. This systematic scoping review will follow ve steps outlined in a framework Page 4/13 proposed by Arksey and O'Malley. (17) The steps are as follows (1) Identify the research question, (2) Identify relevant studies, (3) Study selection, (4) Charting the data, and (5) Collating, summarizing and reporting the results.

Identifying the research question
The research question has been identi ed as: "What is the prevalence and distribution of RE and VI in school-age children in SSA? All studies not published in English, all qualitative studies and all studies that are not primary studies, will be excluded.
The Population Concept Context (PCC) framework will be employed in this study (Table 1). This study search will be conducted using the following databases: Google Scholar

Science direct
PubMed EBSCOhost: CINAHL, Academic search complete, Health-Consumer and Health-Nursing.
The articles found will be exported to a Mendeley library especially created for this study. Thereafter, duplicates will be removed. Table 2 indicates the results of a pilot search. Figure 1 show the screenshot of pilot study done using Science Direct search engine as an example. Suitable studies that are aligned with the inclusion criteria will be exported to a Mendeley library speci cally created for this study done by The Principal investigator (PI), after which all duplicates will be removed. This will be followed by abstract screening (AS), conducted independently by two reviewers, using a tool developed and piloted for this study (Table 3). Full article screening (FAS) will follow, also conducted independently by two independent reviewers using a tool as (Table 4).  All discrepancies will be resolved by the two screeners meeting to reconcile and agree on those studies they initially differed upon. The University of KwaZulu-Natal (UKZN) library will be the primary source for retrieving articles should the authors not respond to such requests. The process of article selection will be reported using the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA), as per Figure 2. Following nalizing of articles, the PI will conduct data extraction on all included articles.
Quality assurance of the study The quality index of all included studies will be determined using the Mixed Method Appraisal Tool (MMAT). This study will employ the 2018 MMAT tool in conjunction with the 2011 version of MMAT tool. The 2018 tool does not provide actual score yet advises that qualitative analysis be provided rather.
However, since this does not have absolute values, the scoring section from the 2011 tool will be adopted with ve criteria from 2018 tool to grade the studies. The scoring ranges from 100% being a good area of study and 20% being low quality. Two independent reviewers will grade the quality of each study's aim, design, methodology and statistical analysis Charting the data An electronic data collection tool to chart evidence that seeks to answer the research question, as shown in Table 5 will be utilized. This tool will extract the necessary information based on prevalence of RE and or VI, distribution of RE and or VI and any impact of RE and or VI on the quality of life. This electronic screening tool will be updated as the need arises during the course of the study. The ndings of this systematic scoping review will be captured onto Microsoft Excel and analysed with the help of a statistician. They will thereafter be published in peer-review journals.

Discussion
The sudden increase in the prevalence of RE in school-going children has been noted recently, especially with the introduction of Edu-comp smart classes in school increasing the use of laptops, as well as increased indoor activities like watching television, using computers and playing mobile phone games.
(19) This is the age group that carries the burden of RE and VI for a longtime as compared to older age groups and they are affected socially and economically. (20) As highlighted earlier, out of 19 million visually impaired children globally, 90% are residing within the developing countries.(21) Sub-Saharan Africa was selected for this review because it consists of the majority of developing countries globally. (21) Therefore, the evidence of this scoping review will guide policy makers and all stakeholders in planning intervention strategies to address this public health concern in low to middle income countries within SSA. To the best of my knowledge, no systematic review or scoping review studies on RE and VI, as well as their impact on the QoL of school-going children in SSA, has been conducted previously. All the data to be used for this scoping review is currently available in the public domain, therefore there is no need for an ethical application or ethical approval.

Ethics approval and consent to participate
All the data to be used for this scoping review is currently available in the public domain, therefore there was no need for an ethical application or ethical approval neither participants consent.

Consent for publication
Not applicable

Availability of data and materials
Data is available from the corresponding author upon the request

Competing interest
The authors declares that the are no con ict of interests

Funding information
All authors are equally responsible for all publication costs of this manuscript and no other funding to disclose Authors' contributions TSS, ZNQ and R conceptualize the study, TSS drafted the protocol, ZNQ and R facilitate and edit the nal manuscript, TSS act as the corresponding author and submit the manuscript for publication purpose.

Disclaimer
The expressed view on this manuscript are those of authors and not necessarily re ect the o cial policy of the University of KwaZulu-Natal. Figure 1 Screenshot of pilot study in Science Direct by the author