Abstract
Objective: This systematic review aims to evaluate the effectiveness of diet and exercise in managing diabetic retinopathy among patients aged 40 to 65 years. It seeks to synthesise qualitative evidence on patient attitudes and experiences related to dietary and physical activity interventions for this condition.
Methods: A qualitative systematic review was conducted with a comprehensive search strategy was employed across PubMed Central, CINAHL, Scopus, and PsycINFO. Initial retrieval yielded 125 studies, which were narrowed down to 32 through date filtering. Subsequent title and abstract screenings reduced the selection to 11 studies. After applying inclusion and exclusion criteria, 8 studies were deemed suitable for detailed review.
Results: The final included studies comprised qualitative and mixed-methods research from the United Kingdom, India, the United States, South Africa, the Netherlands, and the UK. Key findings revealed significant emotional and psychological impacts of diabetic retinopathy, including increased anxiety and depression. Barriers and facilitators to effective management through diet and exercise were identified, with personal motivation, support from healthcare providers, and tailored interventions being crucial. The studies also underscored the importance of coping mechanisms and support systems in managing the condition and its effects on daily life.
Conclusion: This systematic review underscores the need for a holistic, patient-centered approach in managing diabetic retinopathy, considering the psychological, social, and cultural factors that influence patient outcomes. It highlights the importance of tailored dietary and exercise interventions, the role of healthcare providers in ongoing patient support, and the gaps in research regarding exercise’s specific impact on diabetic retinopathy. Public health initiatives must integrate these insights to improve management strategies and address health disparities effectively.
Chapter 1 – Introduction and Literature Review
1.1. Rationale for the research topic
Diabetic retinopathy (DR) is a prevalent public health concern for middle-aged individuals residing in the United Kingdom because DR is a very common disease that affects a large population in the world and has very devastating effects on the health of the eyes (Amoaku et al., 2020). In 2014, DR impacted 54. 6% of type I diabetes patients and 30% of type II patients in the UK, with an overall increase from 9% in 2012 to 36% in 2016 (Denniston et al., 2017). This implies that the burden of DR has remained high, correlating to the increased prevalence of high cholesterol and high blood pressure among adults (Denniston et al., 2017). Thus, the need to establish better ways of managing the condition is still evident. The risk factors for DR are known to include glycaemic control, age, deprivation, and ethnicity. The chances of developing DR rise as one grows older and can also be attributed to poor control of blood sugar levels (Scanlon et al., 2022). In addition, patients from minority ethnic backgrounds and those living in a lower socioeconomic status are more vulnerable to developing DR, especially those with type 2 DM (Haider et al., 2021). These disparities hence call for specific approaches to be put in place to help the needy and vulnerable individuals. As Denniston et al. (2019) pointed out, DR is one of the most common causes of vision loss and blindness among people between the working ages in the UK, thus hurting patients’ quality of life and their work. It also increases the likelihood of developing cataracts or glaucoma to two times that of the normal population (Denniston et al., 2019). The consequences in the sphere of public health are great, as vision loss caused by DR can result in higher healthcare expenses and decreased work efficiency.
The prevalence and management of DR are not uniform across the globe and vary from region to region (Shah et al., 2021). These differences are caused by disparities in health insurance, poverty level, and patient demographics; therefore, practical solutions should be tailored to the targeted geographic location, which is the United Kingdom, in this case, chosen based on the increased incidence and prevalence of diabetic retinopathy condition among the adults (Cai et al., 2021). Based on the aforementioned factors, knowledge of the views regarding diet and exercise regarding DR is timely and relevant. The findings of this study may help refine existing management strategies and alleviate the nuisance of DR in vulnerable populations and geographies. Therefore, aiming at exploring adults’ experience in the UK aged between 40 and 64, this study aims to shed more light on how lifestyle intervention could be approached to enhance clinical outcomes regarding diabetic retinopathy. The findings will help guide the planning of relevant public health interventions and contribute to the creation of patient-centred interventions regarding adherence to non-pharmacological treatments, with the long-term goal of decreasing the incidence and impact of DR.
1.2. Justification of public health issue
The selected area of interest focusing on the effectiveness of diet and exercise in addressing DR for adults within 40-64 years in the UK has high relevance to the general public health practice (Sadiq et al., 2024). This relevance is based on WHO definitions of health and public health as well as conceptual frameworks used in public health.
As per WHO, health is not just the absence of disease or a state of being infirm but rather “a state of complete physical, mental and social well-being” (Cai et al., 2021). Diabetic retinopathy thus affects the physical well-being of those affected by diabetes through vision impairment and blindness. Additionally, the psychological and social aspects of vision loss are other areas of health that may be affected negatively, making it clear that health is multifaceted. Hence, managing DR is in concord with WHO’s broad definition of health and underlines the significance of controlling and preventing chronic diseases for overall well-being (Sunshine et al., 2019).
Consistent with the WHO’s definition of health, other research studies, including findings from studies of Sadiq et al. (2024), Denniston et al. (2017) and Cai et al. (2021) suggest that the increasing prevalence of diabetic retinopathy among adult population is a major public health concern, affecting all aspects of an individual’s life, including mental, emotional, physical and socioeconomic, and thus, further scope of research studies to manage this conditions is justified.
In the context of public health, the problem of DR is closely connected with numerous approaches and standards to enhance the population’s health status. For instance, the Health Belief Model focuses on perceived susceptibility, severity, benefits, and barriers as determinants of behaviours related to health (Denniston et al., 2017). To address these factors and support behaviour change, it is crucial to grasp people’s views on diet and exercise to manage DR. Also, the Socio-Ecological Model acknowledges the effects of individual, group, and environmental factors on health behaviours (Bryl et al., 2022). By understanding the sociocultural contexts of DR lifestyle interventions, the broader determinants of health can be targeted for future public health interventions.
The inability to respond to the problem of DR through research and public health intervention has the following implications. If specific strategies to enhance PA and dietary changes are not implemented, DR may continue or even progress in the future (Praidou et al., 2017). This may well condemn more people to visual impairment and blindness, thereby diminishing their quality of life and imposing a greater financial cost on the healthcare system. Furthermore, inequalities in healthcare and resources are likely to affect DR outcomes, thus perpetuating health inequalities in the population.
1.3. Justification for systematic review
In order to inform public health practice and policy regarding the impact of diet and exercise on DR in adults aged 40 to 64 in the UK, an SR is required. First, a systematic review is employed to provide a comprehensive synthesis of prior qualitative articles to explore views and experiences of people with DR, which is essential for creating interventions that Patients are willing to undertake and put into practice (Pollock & Berge, 2018).
Secondly, since DR is one of the complications of diabetes which is highly prevalent, it is about time to prevent the disease and its effects by utilizing evidence-based preventive measures (Booth et al., 2021). Systematic review helps researchers and policymakers to evaluate the body of published literature and to understand the strengths and limitations of systematic review in informing future research and development of interventions (Elliott et al., 2017). As such, systematic review retains its importance in enhancing the effectiveness of health practice and policy in addressing the increasing challenge of DR.
1.4. Current debate
Attitude towards the effectiveness of diet and exercise in the management of Diabetic Retinopathy
The first and one of the most significant issues arises with the emphasis placed on diabetes control and its effect on the progression of DR through diet and physical activity. Diet and exercise have been believed to possess a relatively higher likelihood of arresting DR progression Lifestyle changes entail diet and exercise, and nutrients such as antioxidants, omega-3 fatty acids, and low glycemic index foods have been said to reduce oxidative stress and inflammation, which are determinants of DR progression (Praidou et al., 2017). Moreover, exercise has been shown to enhance insulin sensitivity and reduce inflammation and endothelial dysfunction, which might contribute to the prevention of microvascular lesions of DR such as macular edema (Ren et al., 2019).
Barriers and Facilitators to Adopting Diet and Exercise Interventions
Many aspects may affect a person’s ability and likelihood to implement those changes into his/her everyday life. For instance, previous research has pointed out that some of the factors that may hinder persons with diabetes from embracing healthy eating practices and exercising include ignorance, a lack of interest, social support, and availability of resources in their society (Loprinzi et al., 2018). However, beliefs about illness causation, cultural practices or values may affect how feasible or relevant those changes are considered by an individual (Shah et al., 2022).
Sociocultural Factors and Contextual Considerations
The third argument is based on the impact of sociocultural and contextual factors on the outcomes of diet and exercise interventions in patients with DR which includes the impact of SES, ethnicity, gender, and cultural beliefs influence the perception of clients towards health and illness and treatment seeking (Mohamed et al., 2019). For instance, it has been observed that health information, services, and literacy vary with poverty status, and minority ethnicity and that these gaps may worsen DR inequalities (Bryl et al., 2022).
1.5. Critical analysis
The current discourses on diet and exercise interventions in DR bring useful information to address this emerging public health problem. On the one hand, findings of earlier publications reveal the presence of evidence regarding the potential effectiveness of lifestyle modifications for the treatment of DR, including diet and physical activity, on the reduction of oxidative stress, inflammation, and microvascular damage, resulting in clinical improvement of DR in patients (Rietz et al., 2022). On the other hand, there are interventions in terms of behaviour changes with educational programs and social support aimed at the promotion of lifestyle changes for the treatment of DR (Luo et al., 2017).
Another literature review, conducted by Bryl et al. (2022) highlights diabetes as a social issue and mentions that proper diet and physical activity are major factors that aid in reducing the risk of ophthalmic complications associated with diabetes. However, the study fails to grasp the qualitative point of view of the patients and follows a more rigorous literature-based knowledge depiction to conclude how the factors of diet and physical activity affect the management of DR.
Nevertheless, a critical evaluation of the current literature highlights some of the limitations and research gaps as follows. Firstly, there is less emphasis on qualitative research, despite its potential to shed light on patients’ and clients’ perceptions of diet and exercise interventions for DR management. Implementing qualitative research is important because it provides information on the sociocultural factors, perceptions, and facilitators or barriers to behaviour change. Furthermore, there is a dearth of studies that examine the follow-up and long-term outcomes of the efficacy of lifestyle changes in various populations. In addition, the current literature lacks the focus on inequities in the distribution of resources, and health care services that can potentially widen DR disparities between disadvantaged and ethnically diverse populations.
1.6. Literature gap
The gap in the literature is evident in the scarcity of qualitative studies mainly focusing on people’s views on diet and exercise regarding DR. This study seeks to address this gap through a systematic review of the qualitative studies that can help to inform the understanding of the lived experiences, beliefs and attitudes of adults aged 40 to 64 residents in the UK. By integrating data from the qualitative studies, the research will provide a holistic understanding of the determinants of behaviour change and adherence to lifestyle changes for DR management. It thus helps in the development of patient-centred interventions that will make clinical outcomes better and boost public health practice.
1.7. Research question
The research question:
“What are the views about the effectiveness of diet and exercise in the management of diabetic retinopathy among patients aged between 40-65 years?”
The above research question aligns with the known gaps in the literature, which, in this study, is focused more on understanding the personal knowledge, orientation, attitude and views of diabetic retinopathic patients aged between 40-65 years. The population of interest aligns with the population group that was found to have the highest prevalence as per the literature review conducted above. Understanding the qualitative aspects of patients’ knowledge and opinions, on how their diet and physical activity affect the management of DR, is thus, the key research question that this systematic review will focus on.
1.8. Research aim
The purpose of this systematic literature review is to synthesize qualitative data to explore opinions on the effectiveness of diet and exercise in treating diabetic retinopathy.
1.9. Research objectives
- To examine knowledge, perceptions, and practices concerning lifestyle change for DR in adults in the UK.
- To assess the perceived efficacy of diet and exercise in addressing diabetic retinopathy among the target population.
- To discuss factors that hinder and enhance the use of diet and exercise interventions in managing diabetic retinopathy.
- To formulate recommendations for public health policies and practices that will enhance the practice of lifestyle interventions for diabetic retinopathy.
1.10. Signposting
The structure of the dissertation is coherent, as in the first chapter, Introduction and Literature Review, the context of the work is outlined, and the current literature on the effectiveness of diet and exercise intervention in DR is discussed in detail. Chapter 2 elaborates on the approach that was used in conducting the systematic review, including the search methods, eligibility criteria and the methods of analysis. Chapter 3 of this book discusses the systematic review, highlighting the findings from the qualitative data and the themes derived from them. The Discussion Chapter 4 synthesises the findings, reviews relevant literature and the contribution of the study to practice in the field of public health. Lastly, Chapter 5 provides a conclusion that outlines the major implications and recommendations for subsequent research and policy initiatives.
Chapter 2 – Methodology
2.1. PEO and Review Question
The objective of this dissertation is to perform an SR of the qualitative research to explore the understandings of the efficacy of dietary and physical activity interventions for DR in 40–64-year-old people in the UK. This paper in this review aims to use the qualitative research approach to capture the participants’ emotions, attitudes and perceptions towards lifestyle interventions, a method that quantitative surveys may fail to notice (Munn et al., 2018; Braun and Clarke, 2022).
When identifying the articles’ search terms and keywords, the PEO (Population, Exposure, Outcome) model was employed to design the most appropriate search strategy. The PEO approach is especially helpful for qualitative research because it makes it easier to find studies that focus on the participants’ perspectives. The following table indicates the various subdomains of PEO based on the current research question and area of focus.
Table 1: PEO framework used to demonstrate different aspects of the research question. Source: Self made
The review question for this research is “What are the perspectives on the efficacy of diet and exercise in the management of diabetic retinopathy among adults aged 40 to 64 years in the UK”. The review questions aim to collect abstract data on the perception of people on how diet and exercise affect the management of diabetic retinopathy among people of a defined age group, where the prevalence of the condition is deemed to be higher.
2.1.1. Search Strategy and Keywords
The search was conducted using three primary databases: PubMed, Scopus, and PsycINFO datasets where the corresponding papers are published regularly. These databases were selected because they cover a broad range of periodical literature, particularly in the health and sciences and psychology sub-field.
1. PubMed: Although occurring primarily in biomedical and health articles, PubMed is well-loved for its comprehensive index and Web access. It includes all types of research articles, journals, clinical trials, original investigations, and systematic reviews following diabetic retinopathy and its management (Leclerq et al., 2019).
2. Scopus: This comprehensive bibliographic database contains a broad spectrum of scientific periodicals, and is among the major sources providing several sciences, embracing such fields as medicine, social sciences and health sciences. Since Scopus is a humongous database that houses a diverse multitude of peer-reviewed journals, it is ideal for obtaining a wide range of views on a given topic (Lee et al., 2023).
3. PsycINFO: PsycINFO has its coverage of literature in psychology and related disciplines and is owned by the American Psychological Association. The above database is highly relevant for documenting behavioural and psychosocial aspects of DR management, including patient compliance and psychological reactions to changes in behaviour (Schotten et al., 2017).
2.1.2 Search Terms and Keywords
Table 2: Key search terms included
Source: Self Made
To increase the search accuracy MeSH (Medical Subject Headings) terms and Boolean operators were used and the following is brief information on them as used for the search:
MeSH Terms: A MeSH term used mostly in PubMed it is used to retrieve articles that fall under a certain Medical Subject Heading so that no articles with related topics are left out due to the difference in the used terms. For instance, “Diabetic Retinopathy” [Mesh], “Diet” [Mesh], and “Exercise” [Mesh] were employed to locate all the related works under these categories.
Boolean Operators: These were used to narrow and expand the search area respectively.
- AND: Required all keywords must be included in the lists of findings including the following example of the final Boolean search terms: ‘diabetic retinopathy AND diet AND exercise AND perspectives AND qualitative’ (Atkinson and Cipriani, 2018).
- OR: Facilitated an opportunity to find any of the words in the search line and was particularly useful in case the search line has similar words like synonyms or if the search contains phrases like “diet and nutrition and eating habits” (Scells et al., 2020).
- NOT: Continue to filter out terms related to the study but unrelated to the topic to refine the search and focus only on the relevant studies.
2.1.3. Search Strategy Example
The following table shares an example of the search strategy used in PubMed, as explained above:
Table 3: Example of search strategy using keywords and Boolean operators.
Source: Self made
| 1. Senior citizens | 4. perspective | 8. nutrition | 14. Diabetic retinopathy |
| 2. Patients | 5. experience | 9. diet | |
| 3. Diabetic patients | 6. opinion | 10. exercise | |
| 19. UK | 7. thoughts | 11. physical activity | |
| 12. workout | |||
| 13. meal | |||
| 15. Combine 1, 2, 3 and 19 using ‘OR’ | 16. Combine 4, 5, 6 & 7 using ‘OR’ | 17. Combine 8, 9, 10, 11, 12, & 13 using ‘OR’ | Combine 15, 16, 17 & 14 using ‘AND’ |
2.1.4. Search Execution
The first level of search elicited a general search that gave a very broad scope of articles which formed the basis of the study as mentioned by Majid and Vanstone (2018). The search was then refined through the application of filters to identify articles that reported on the qualitative perceptions and experiences of UK-only, adult men and women between 40 to 64 years with DR interested in physical activity and diet. Through this approach, it was easier to select several papers about the research question but exclude the over-acquisition of information. Through these databases and search strategies, the review should gather and summarise the qualitative evidence, to offer an improved picture of the actual daily lives and attitudes of the patients who go through diabetic retinopathy while employing lifestyle changes (Maguire and Delahunt, 2018).
2.2. Justification of Search Criteria
The guiding the selection or exclusion of the studies for this qualitative SR (Systematic Review) was designed to guarantee the relevance, rigour, and quality of the final sample of the studies to be reviewed (Munn et al., 2018). This approach makes it easier to capture various views about diet and exercise as an effective measure in managing DR among the targeted adult population (aged 40 to 64 years) in the UK.
First, the research design became the main criterion for inclusion and here we selected only qualitative research studies (Thomas et al., 2020). This includes designs like interviews, focus groups and ethnographical studies which offer more information about the experiences, opinions and attitudes of individuals. The rationale for using this type of review is thus on the basis that it enables the researcher to identify and explain qualities of studies that cannot be easily measured by quantitative tools. As this review focuses on the quality of the material offered, it is expected to capture the specific and individual aspects of managing DR through lifestyle changes – crucial for designing efficient patient-oriented and population health approaches (Murphy, 2017).
Randomised controlled trials were excluded as such study designs are not as amenable to answering those research questions related to the subjective experience of individuals. By their nature, quantitative outputs are useful for outcome quantification and statistical consistencies and discrepancies but are insufficient for the specificity required by this review. Therefore, excluding quantitative research helps to keep the synthesis integrated with the subject of study, which is qualitative research (Murphy, 2017).
Filter by year of publication was set between 2010 and 2024. Such an approach was used to consider the most recent and up-to-date studies, giving the modern concept and management of DR. The year 2010 is considered for analysis as the ten years from this year reflect a growing trend in lifestyle modifications in the management of chronic diseases. It also corresponds to the improvement of diabetes treatment and growing interest in the psychosocial aspects of health-related behaviours, making sure that the review includes recent and more relevant studies (Page et al., 2021).
There were other important factors as well, namely language requirements. As for the selection criteria, only articles published in English were considered for this review. This was done to make the review manageable due to the language skills of the researchers. This way, limiting the sources to English-speaking countries also eliminates translation issues that might otherwise introduce biases in the data analysis and reporting of qualitative research results (Murphy, 2017).
Concerning publication type, the review was limited to the primary research articles only. One of the advantages of primary research is that it offers first-hand information that consists of qualitative or quantitative data, or both, depending on the research questions of this review. Moreover, editorials, commentaries, and review papers were not included in the present analysis as these types of publications do not contain results of new investigations but rather reflect personal views, summaries, or further analysis of the existing data. The review is restricted to only primary sources to ensure that the sources used are original and empirical and hence increase their validity and reliability.
Table 4: Inclusion and Exclusion Criteria
Source: Self Made
| Criteria | Inclusion | Exclusion |
| Research Design | Qualitative studies (e.g., interviews, focus groups, ethnographic studies) | Quantitative studies (e.g., surveys, RCTs, cohort studies) |
| Outputs | Qualitative outputs | Quantitative outputs |
| Publication Years | 2010 to 2024 | Studies published before 2010 |
| Language | English | Non-English languages |
| Publication Type | Primary research articles including theses and dissertations from reputed sources | Editorials, commentaries, review papers |
| Population | Adults aged 40 to 64 with diabetic retinopathy in the UK | Studies involving children, adolescents, or elderly |
| Geographic Location | Studies conducted in the UK |
2.3. Selection of Studies
As for the search process for papers to be included in the current qualitative systematic review, this process has been orderly and well-ordered as only quality research papers and the ones most relevant to the given topic were included (Page et al., 2021). A PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) flow diagram is included in Appendix 2.1, to showcase
2.3.1. Conducting the Search
The initial step involved conducting comprehensive searches across the selected databases: The targeted databases for the current study included PubMed, Scopus, and PsycINFO databases. To focus on all articles related to the identified PEOs, the searches have been developed and included all predefined terms and keywords. The article sources focused on the perspectives on diet and exercise about DR among adults aged 40 to 64 years in the United Kingdom. Additional filters such as Boolean operators and MeSH terms were applied to optimize the search outcomes. This created a pool of articles that contains all studies that may fit the inclusion criteria for the study at hand.
2.3.2. Selecting Initial Papers
After the identification of databases, the papers were included or excluded based on the titles and abstracts of the papers. This step was designed to filter through the records that looked promising in response to the research question and disregard studies that had no value for the research. The title and abstract of each paper were evaluated to determine if the specific study provided information on qualitative aspects of DR in relation to diet and exercise. This was the time to make sure that as many possible studies as possible could be included in the analysis.
2.3.3 Removing Duplicate Papers
That was followed by screening and removal of any duplicate papers that may have been available in the repository. This is because the search was conducted in more than one database and as such, many articles were found in more than one database. They were then compared and later on, using reference management software duplicates were eliminated from the subsequent screening stages of the process. This helped avoid the repetition of work as the articles went through this process before reaching the reviewers.
2.3.4. Title Screening
In a second step, a second round of title screening was performed once all the duplicates had been eliminated. It also involved a more detailed scrutiny of the titles so as to ascertain whether they reflect the exact theme of the review to be conducted. Papers without relevant titles that could not easily be associated with the qualitative approaches to diet and exercise for DR management were also eliminated. This step helped to narrow down the results even more before applying inclusion criteria to the studies.
2.3.5. Abstract Screening
The next step was the scrutiny of abstracts of the more extensive studies that survived the first culling. Titles and abstracts were reviewed to check if the included investigations used qualitative approaches, addressed the target population (adults between 40 to 64 years with DR in the UK) and explored diet and exercise perceptions. This screening step was important given it allowed us to examine whether the studies under analysis corresponded to the research question and general inclusion criteria.
2.3.6. Full-Paper Screening
Upon identifying studies that met the criteria set during the abstract screening, the researchers sought the full manuscripts for detailed assessment. This was the very last step of the screening process where each paper was checked against all eligibility criteria for the final assessment (Fig 1 PRISMA flowchart, shows the screening process and the count of papers deemed suitable for inclusion after each step). The relevant literature was appraised based on their methodological quality and the relevance of the data they provided on the qualitative dimensions. This step also made sure that only the best research papers were included in the final review to increase credibility.
2.3.7. Final Confirmation of Papers
The last of the paper selection techniques was the verification of the chosen papers. It was then re-evaluated all the identified studies that passed the full-paper screening to confirm adherence to the inclusion criteria while excluding any of the studies that had any of the exclusion criteria. Disagreements or ambiguities on the aspects being measured were handled in consultation with the research team and addressing all the aspects of the studies seen in the systematic review.
2.4. Study Quality Assessment
In light of the formulated aim and objectives, the papers obtained were critically appraised for quality using the Critical Appraisal Skills Programme (CASP) qualitative studies checklist. CASP was chosen because of its credibility and applicability and because it was considered appropriate for the assessment of the quality of the qualitative papers as the current systematic review suggested. The CASP checklist has attracted more attention because it gives an appearance that it is more appropriate for researchers in literature than others as it is a comprehensive tool for assessing the quality, reliability, and relevance of qualitative research studies. It also follows a logical and structured workflow, thereby eradicating the possibility of inference as this pertains to the assessment of the methodological quality of the studies based on the information reported by Buccheri and Sharifi (2017).
The CASP checklist that is to be used in the appraisal comprises ten questions (questions from the CASP checklist for Qualitative Studies have been provided in the Appendix A along with a brief description of the use of these questions). The following set of questions can be considered as belonging to the given type of study more adequately, the need for its further continuation, its importance, potential for development, means and characteristics. The first question is based on the framework and entails evaluating the research question and asking whether or not it corresponds to the aim and the objectives of the study (Long et al., 2020). This is crucial as it outlines the scope against which the subsequent parts of the study would be evaluated, given the fact that there are proposed changes to the perception of diet and exercise management of Diabetic Retinopathy.
The second question helps decide on the relevance of the chosen qualitative method of inquiry. This entails checking the feasibility of the method used in undertaking the research and answering the research question. In case this review aims at offering a combination of personal and subjective narratives, it is required to use qualitative methods like interviews, focus groups or ethnography as below mentioned research (Wang et al., 2020). Regarding the study most useful to provide detailed data about it and regarding the patient’s own reported patient lived experiences of diabetic retinopathy of patients included in lifestyle change and intervention.
Additional questions that are present in the CASP checklist are oriented to investigate the extent to which the used research design and conduct are logical and proactive. This relates to the assessment of how the study participates in the identification of the sampling strategy and the provision of a satisfactory justification of this strategic component (Buccheri, & Sharifi, 2017). The selected studies should also describe the details of the sampling methods which helps identify the participants for the main study because they would involve a population of interested adults aged between 40-64 years with DR in the UK. Additionally, the checklist assesses the steps that have been followed in the data collection process and determines whether the used method was suitable for obtaining the qualitative information. This also includes the assessment of the usefulness of such non-SW structures as interview guides and the frequency of the ratios of reported data collection activities.
CASP also plans to consider the general ethical issues that are related to the specific research that is conducted to contribute to the systematic review process. This paper defined the ethical consideration in the research process as a deliberate endeavour to consider certain ethical concerns that may be of concern in the particular study like the consent to be given for the study or the participant’s confidentiality as demonstrated by Buccheri and Sharifi (2017). Like any other study, several general ethical considerations should be followed in conducting a qualitative study to respect the participant and ensure that ‘paradigm purity’ is observed.
The last area when fundamental aspects recognized by the CASP checklist are taken into account is concerning data analysis. They further realized that the tool reveals how appropriate or otherwise the level of analysis is, and whether the conclusions derived are data-driven or not (Long et al., 2020). Those things include features such as the kind of coding frameworks used or reporting back of the analytical process followed and the conclusions made are therefore all rooted back to the participants.
Finally, the focus will be towards the credibility and relevance of the source mentioned in the checklist. This involves assessing the quality of the documented results which in essence measures the quality of the research work done and the extent to which it enriches knowledge. As derived from the above discussion, the following is the perception of the author about the outcome of the current literature review: Due to the above-discussed lack of knowledge about diet and exercise management of DR, the findings of the current literature review will have to be useful in responding to questions on diet and exercise for the management of DR to assist practice and policy in public health (Wang et al., 2020).
2.5. Data extraction
The process of data extraction entails the work of extracting relevant data and information from the selected papers, which can be then combined in a format such as a data extraction table. Several key data and information, such as the participant characteristics, year of data collection, study design, funding and other information can be collated with such data extraction table (Higgins and Thomas, 2019). Therefore, the JBI i. e. Joanna Briggs Institute data extraction tool for qualitative research was considered appropriate for this study since the use of a standardized data extraction tool ensures the uniformity in the data obtained from different studies (JBI, 2020).
2.6 Data Synthesis
The main objective of any systematic review is to make conclusions based on the collected data. To capture the older diabetic retinopathy patients’ perceived effectiveness of diet and exercise in managing the condition, it was appropriate to use a thematic analysis. Any analysis of collected data entails the researchers to look for themes or patterns from the data and make conclusions based on the themes (Higgins and Thomas, 2019). This also enables the researchers to focus only on the current research question, assess the findings section of each research paper, code the findings section and generalize the codes to generate the themes.
2.7 Summary of Chapter
This second chapter explained the systematic procedures followed by the researcher to carry out the search for the qualitative papers to respond to the current research question. As stated in this chapter, the next chapter provides the data extraction table and the results compiled from the identified studies based on the processes outlined in this chapter.
Chapter 3: Results
3.1. Results of Search Strategy and Study Selection
As a starting point in the search process, an independent search was conducted using several primary databases. The databases used in this systematic review were PMC, CINAHL, Scopus, and PsycINFO. As outlined in the previous chapter, each database was searched using the keywords and search terms outlined below. These search terms were selected to ensure a broad yet targeted retrieval of studies relevant to the research question: It is particularly important to understand the perceptions of the role of diet and exercise in the prevention and treatment of diabetic retinopathy among patients 40 to 65 years of age.
The first search using these databases provided a total of 125 articles. In order to further narrow down the outcomes, the date filter was used, thus providing the studies published only after the year 2012. This temporal limitation was meant to provide a more contemporary view of the subject area and its advancements. After applying the date filter, the total number of studies available was brought down to 32. A sample of the search made in the PubMed Central database is provided in Appendix B, which shows the use of keywords and Boolean operators.
In the next step, the titles of these 32 articles were carefully screened to assess their relevance for this systematic review. The first step in the title screening was designed to eliminate any study that could not be reasonably related to the research question. Thus, 21 articles were viewed as irrelevant and were removed based on the title, and 11 articles were considered to be relevant and were included based on the title analysis.
The next step was to review the abstracts of these 11 studies identified in the previous step. This abstract screening process was important to identify whether the studies met the inclusion and exclusion criteria formulated for this review. After screening the abstracts, three studies were removed because they do not meet the requirements, thus, eight studies were included for further analysis.
While this systematic review mainly sought to identify the ways by which DR can be managed in a UK-based patient population, the shortage of research on the topic limited to the UK patient population meant that studies on other patients were also incorporated into the analysis. This decision was taken so that no study published on this subject was left uncovered, even if the studies were conducted in different regions.
The list of studies was screened again in the second step to ensure that all the identified studies met the inclusion and exclusion criteria. This final assessment led to the identification of 8 studies that satisfied all requirements for the review. In combination, these studies offered knowledge on the feasibility of diet and exercise in the diabetic retinopathy of the targeted age group of 40-65 years.
The other articles were excluded on the basis of methodological factors. In particular, the review focused on the exclusion of the studies that did not include qualitative methods in the investigation. Also, some papers were excluded because of the discrepancy in the analyzed population, as in different age groups, gender, or different diabetic conditions than what was under investigation in the review. One study was also left out because its geographic setting could not be compared with the socio-economic environment of the UK.
To visually represent the study selection process, a PRISMA flow diagram (Moher et al., 2009) has been included below. PRISMA, which stands for The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA, 2015), provides a standardized framework for reporting systematic reviews, ensuring transparency and clarity in the presentation of findings (Liberati et al., 2009). The diagram illustrates the stages of the study selection process, including the initial number of studies retrieved, the reduction in studies following date filtering, the number of studies assessed based on titles and abstracts, and the final number of studies included in the systematic review.
Figure 1: PRISMA flowchart showing a selection of studies
Source: Self made
Table 5: List of included studies
| Serial. No. | Included Studies |
| 1. | Devenney, R. and O’Neill, S., 2011. The experience of diabetic retinopathy: A qualitative study. British journal of health psychology, 16(4), pp.707-721. https://doi.org/10.1111/j.2044-8287.2010.02008.x |
| 2. | Tripathi, D., Vikram, N.K., Chaturvedi, S. and Bhatia, N., 2023. Barriers and facilitators in dietary and physical activity management of type 2 diabetes: Perspective of healthcare providers and patients. Diabetes & Metabolic Syndrome: Clinical Research & Reviews, 17(3), p.102741. https://doi.org/10.1016/j.dsx.2023.102741 |
| 3. | Beaser, R.S., Turell, W.A. and Howson, A., 2018. Strategies to improve prevention and management in diabetic retinopathy: qualitative insights from a mixed-methods study. Diabetes Spectrum, 31(1), pp.65-74. https://doi.org/10.2337/ds16-0043 |
| 4. | Burton, A.E., Gibson, J.M. and Shaw, R.L., 2016. How do older people with sight loss manage their general health? A qualitative study. Disability and rehabilitation, 38(23), pp.2277-2285. https://doi.org/10.3109/09638288.2015.1123310 |
| 5. | Murphy, T., 2019. Diet composition and perceptions around food in individuals with Type 2 Diabetes Mellitus following a long-term low carbohydrate high-fat diet. https://open.uct.ac.za/bitstreams/c40c248d-a39f-43ad-b6ce-7dadad518e8e/download |
| 6. | McHardy, M., 2015. Necessity, Concepts and Feasibility of Culturally Tailored Diabetes Education for Migrants in the Netherlands and the United Kingdom: A Qualitative Study on Experts’ Views https://reposit.haw-hamburg.de/bitstream/20.500.12738/7129/1/Miriam_McHardy_MA.pdf |
| 7. | Fan, C., Liu, Y., Huai, B., Sheng, Y., Wu, T., Gao, W., Chen, H., Wang, H. and Wang, Y., 2023. Disease perception and experience in people with diabetic retinopathy: A qualitative study. Nursing Open, 10(4), pp.2150-2157. 10.1002/nop2.1462 |
| 8. | Sturrock, B.A., Rees, G., Lamoureux, E.L., Wong, T.Y., Holloway, E. and Fenwick, E.K., 2018. Individuals’ perspectives on coping with vision loss from diabetic retinopathy. Optometry and Vision Science, 95(4), pp.362-372. 10.1097/OPX.0000000000001209 |
3.2. Quality Assessment
To ensure the quality of the included studies was high the CASP (2018) appraisal tool was used. The Full CASP appraisal tool can be found in Appendix D.
3.3 Data Extraction
The data was extracted by hand using the Joanna Briggs Institute (JBI) (2020) data extraction tool for qualitative research and then inputted into a data table using Microsoft Word. Three separate tables are included in this section to make the data clearer and more accessible. They include Study information, methodology and study design, participant characteristics and themes identified. The full version of the JBI tool (2020) can be found in Appendix C.
Table 6: Data Extraction of Included Studies
| Author/Year | Study Design | Study Aims/Objectives | Study Participants | Settings | Country | Data Collection Method | Key Findings |
| Devenney & O’Neill, 2011 | Qualitative | To explore the personal experience of diabetic retinopathy | Diabetic retinopathy patients | Healthcare settings | United Kingdom | Semi-structured interviews | Participants experienced significant emotional and psychological impacts, including fear and anxiety, exacerbated by visual impairment. Themes included adaptation to vision loss, emotional distress, and impact on daily life. |
| Tripathi et al., 2023 | Mixed-methods | To identify barriers and facilitators in managing type 2 diabetes through diet and exercise | Healthcare providers and type 2 diabetes patients | Healthcare facilities | India | Surveys and interviews | Barriers included a lack of resources and support, while facilitators included personal motivation and support from healthcare providers. The study highlighted the need for tailored interventions and continuous support. |
| Beaser et al., 2018 | Mixed-methods | To gather qualitative insights on strategies for improving diabetic retinopathy management | Diabetic retinopathy patients and healthcare providers | Various clinical settings | United States | Focus groups and interviews | Effective management strategies included education, regular screenings, and personalized treatment plans. Emphasized the need for improved communication between patients and healthcare providers. |
| Burton et al., 2016 | Qualitative | To understand how older individuals with sight loss manage their overall health | Older adults with sight loss | Community and healthcare settings | United Kingdom | In-depth interviews | Participants used strategies like reliance on caregivers and adaptive technologies. Themes included resilience, coping strategies, and the role of social support. |
| Murphy, 2019 | Qualitative | To examine the dietary composition and perceptions around food in individuals on a low-carbohydrate high-fat diet | Type 2 diabetes patients | Clinical or community settings | South Africa | In-depth interviews | Participants reported improved glycemic control and high satisfaction with their diet. Themes included dietary adherence, perceived health benefits, and the impact of diet on daily life. |
| McHardy, 2015 | Qualitative | To explore the necessity and feasibility of culturally tailored diabetes education for migrants | Diabetes education experts | – | Netherlands and the UK | Semi-structured interviews | Culturally tailored education is essential for addressing the specific needs of migrant populations. Themes included cultural barriers and the need for more inclusive educational materials. |
| Fan et al., 2023 | Qualitative | To investigate disease perception and experiences of individuals with diabetic retinopathy | Patients with diabetic retinopathy | Healthcare settings | Semi-structured interviews | Emotional responses like fear and frustration were common. Themes included the impact on quality of life, coping mechanisms, and the need for better patient support. | |
| Sturrock et al., 2018 | Qualitative | To explore perspectives on coping with vision loss from diabetic retinopathy | Patients with diabetic retinopathy | Various clinical settings | Semi-structured interviews | Coping strategies involved personal adjustment and external support. Themes included adaptive strategies, emotional challenges, and the role of healthcare providers. |
The examination of diabetic retinopathy through the eyes of the affected patients was carried out by Devenney and O’Neill (2011). According to the researchers, semi-structured interviews revealed how these people perceive their health status. A lot of emotional suffering was experienced by the respondents including anxiety and depression associated with visual difficulties which also affected their overall functioning. The themes identified in this research design were adaptation to vision loss, the psychological burden of disease, self-efficacy and societal functioning. This research study contributes considerably towards understanding psychological aspects that people living with diabetes go through hence making them feel like some measures such as changing diet or engaging in sports are useful in controlling diabetes.
In a study that employed mixed methods, Tripathi and coworkers (2023) sought to determine what barriers and facilitators exist in managing type 2 diabetes through diet and exercise from the viewpoint of healthcare practitioners as well as patients. Surveys and interviews were used in their research, which revealed critical challenges such as insufficient resources and lack of support. Facilitators encompass personal motivation and assistance from health care professionals. The need for customized interventions and ongoing assistance aimed at the efficient management of diabetes was spotlighted in this study, stressing on patient’s involvement as well as the healthcare provider’s participation. This article relates to the review by identifying aspects affecting the management of type 2 diabetes that can have an impact when it comes to dealing with diabetic retinopathy; these include consuming appropriate diets or engaging in regular physical activities.
Management of diabetic retinopathy can be improved through various methods as shown by Beaser et al (2018) who used a mixed-methods approach. They identified effective management strategies including patient education, regular screenings and individualized treatment plans through focus groups and interviews with patients and healthcare providers. According to their results, clear communication between patients and healthcare providers is vital for better disease management and patient outcomes. This study resonates well since it provides strategies for managing diabetic retinopathy vis-à-vis the review’s focus on dietary practices and exercise in this area.
Burton et al. (2016) conducted an in-depth qualitative interview study with older adults who have lost their sight to examine how they maintain their general health. This investigation showed that participants were able to avert various forms of health problems by utilizing different methods such as depending on caregivers and utilizing adaptive technologies. Important concepts included resilience, the need for social support, and diverse approaches that helped people cope with their overall health even when they had lost a lot of their eyesight. Therefore, this research enhances understanding of how patients deal with health problems associated with vision loss which is important in assessing the effect of eating habits and physical training on diabetic retinopathy.
Murphy (2019) examined the effects of a long-term low carbohydrate high-fat diet on individuals with Type 2 Diabetes Mellitus through qualitative interviews. The study found that participants on this diet reported improved glycemic control and expressed high levels of satisfaction with their dietary regimen. The key themes included dietary adherence, perceived health benefits, and the impact of diet on daily life and diabetes management, highlighting the positive effects of dietary modifications on health outcomes. This study is relevant as it provides evidence on dietary interventions, which is a critical aspect of managing diabetic retinopathy.
McHardy (2015) investigated the requirement and practicality of culturally adapted diabetes education for expatriates in Holland and Britain. Employing semi-structured interviews with experts in diabetes education, this study has established a need for educational programs that address cultural barriers and specific needs of migrant populations. The themes included the challenges faced in providing culturally relevant education and how including various patients from different backgrounds is important in creating educational materials. This study is relevant as it highlights the importance of tailored educational interventions, which can influence the effectiveness of diet and exercise strategies for managing diabetic retinopathy.
Fan et al. (2023) conducted a qualitative study that used semi-structured interviews to investigate the understanding of sickness and experiences among those diagnosed with diabetes mellitus-related retinal degeneration. Their research revealed various feelings towards losing eyesight, including fear and disappointment. The findings indicated that diabetic retinopathy significantly affects individual lifestyles; patient coping styles were identified while also underscoring the necessity for advanced support systems for managing both psychological and physical elements. This piece is pertinent to this dissertation because it discusses the persons’ perspectives and experiences that are significant in shaping their participation in diet and physical activity interventions.
The research by Sturrock et al. (2018) focused on how people with diabetic retinopathy cope with vision loss using qualitative interviews. Coping strategies were found to include both personal adjustments and outer supportive measures. Adaptive methods, emotional struggles and healthcare providers’ support for adaptation were among the themes discovered in the study. The importance of holistic support systems for helping individuals navigate difficulties posed by visual disabilities and improving their general welfare was also brought out by this study. This study is relevant as it explores coping strategies that may intersect with dietary and exercise management in diabetic retinopathy.
3.4. Summary of Chapter
This chapter presents the results from the systematic review, focusing on the data extracted from the selected studies. It emphasizes the crucial information to consider when evaluating and including studies in a systematic review. The synthesized findings are discussed in detail in Chapter 5. The subsequent chapter will identify and explore the primary themes emerging from the thematic synthesis.