Artificial intelligence-supported diabetic retinopathy screening in Tanzania: rationale and design of a randomised controlled trial.

INTRODUCTION: Globally, diabetic retinopathy (DR) is a major cause of blindness. Sub-Saharan Africa is projected to see the largest proportionate increase in the number of people living with diabetes over the next two decades. Screening for DR is recommended to prevent sight loss; however, in many low and middle-income countries, because of a lack of specialist eye care staff, current screening services for DR are not optimal. The use of artificial intelligence (AI) for DR screening, which automates the grading of retinal photographs and provides a point-of-screening result, offers an innovative potential solution to improve DR screening in Tanzania. METHODS AND ANALYSIS: We will test the hypothesis that AI-supported DR screening increases the proportion of persons with true referable DR who attend the central ophthalmology clinic following referral after screening in a single-masked, parallel group, individually randomised controlled trial. Participants (2364) will be randomised (1:1 ratio) to either AI-supported or the standard of care DR screening pathway. Participants allocated to the AI-supported screening pathway will receive their result followed by point-of-screening counselling immediately after retinal image capture. Participants in the standard of care arm will receive their result and counselling by phone once the retinal images have been graded in the usual way (typically after 2-4 weeks). The primary outcome is the proportion of persons with true referable DR attending the central ophthalmology clinic within 8 weeks of screening. Secondary outcomes, by trial arm, include the proportion of persons attending the central ophthalmology clinic out of all those referred, sensitivity and specificity, number of false positive referrals, acceptability and fidelity of AI-supported screening. ETHICS AND DISSEMINATION: The London School of Hygiene & Tropical Medicine, Kilimanjaro Christian Medical Centre and Tanzanian National Institute of Medical Research ethics committees have approved the trial. The results will be submitted to peer-reviewed journals for publication. TRIAL REGISTRATION NUMBER: ISRCTN18317152.

Artificial intelligence for diabetic retinopathy in low-income and middle-income countries: a scoping review.

Diabetic retinopathy (DR) is a leading cause of blindness globally. There is growing evidence to support the use of artificial intelligence (AI) in diabetic eye care, particularly for screening populations at risk of sight loss from DR in low-income and middle-income countries (LMICs) where resources are most stretched. However, implementation into clinical practice remains limited. We conducted a scoping review to identify what AI tools have been used for DR in LMICs and to report their performance and relevant characteristics. 81 articles were included. The reported sensitivities and specificities were generally high providing evidence to support use in clinical practice. However, the majority of studies focused on sensitivity and specificity only and there was limited information on cost, regulatory approvals and whether the use of AI improved health outcomes. Further research that goes beyond reporting sensitivities and specificities is needed prior to wider implementation.

Gender bias within a diabetic retinopathy screening programme in Tanzania.

BACKGROUND: The Kilimanjaro Diabetic Programme has been running since 2010 and screens persons with diabetes for diabetic retinopathy (DR). It was noted that women were less likely to attend follow-up appointments compared to men. The aim of this study was to explore gender biases amongst persons registered with the screening programme. METHODS: A prospective mixed-methods study was carried out using a questionnaire of closed-ended questions and a semi-structured interview guide. RESULTS: Of the 300 participants included in the quantitative component of the study, 193 (64.3%) were female and 107 (35.7%) were male. Females were significantly less educated (p < 0.001) and self-reported as less likely to attend the tertiary hospital if referred (p = 0.022). Of the married participants, on multivariate analysis, men were significantly more likely to make both financial decisions in the household (p = 0.001) and to decide if, and when, family members should attend hospital compared to women (p = 0.0048), independent of age, education level and whether they were from an urban or rural area. Qualitative analysis of the 33 interviews revealed a good understanding of the threat to vision from DR, but limited appreciation of disease chronicity. A common theme was that men are regarded as the head of the household and therefore make the financial decisions; this was especially true in less educated families. CONCLUSION: As screening and treatment facilities for DR are developed in SSA, it is important that strategies are employed to reduce the burden of blindness and visual impairment from the under-utilisation of diabetic eye care services by women.

Prevalence, Risk Factors, and Complications of Diabetes in the Kilimanjaro Region: A Population-Based Study from Tanzania.

BACKGROUND: In sub-Saharan Africa, diabetes is a growing burden, yet little is known about its prevalence, risk factors, and complications. To address these gaps and help inform public health efforts aimed at prevention and treatment, we conducted a community-based study assessing diabetes epidemiology. METHODS AND FINDINGS: We conducted a stratified, cluster-designed, serial cross-sectional household study from 2014-2015 in the Kilimanjaro Region, Tanzania. We used a three-stage cluster probability sampling method to randomly select individuals. To estimate prevalence, we screened individuals for glucose impairment, including diabetes, using hemoglobin A1C. We also screened for hypertension and obesity, and to assess for potential complications, individuals with diabetes were assessed for retinopathy, neuropathy, and nephropathy. We enrolled 481 adults from 346 urban and rural households. The prevalence of glucose impairment was 21.7% (95% CI 15.2-29.8), which included diabetes (5.7%; 95% CI 3.37-9.47) and glucose impairment with increased risk for diabetes (16.0%; 95% CI 10.2-24.0). Overweight or obesity status had an independent prevalence risk ratio for glucose impairment (2.16; 95% CI 1.39-3.36). Diabetes awareness was low (35.6%), and few individuals with diabetes were receiving biomedical treatment (33.3%). Diabetes-associated complications were common (50.2%; 95% CI 33.7-66.7), including renal (12.0%; 95% CI 4.7-27.3), ophthalmic (49.6%; 95% CI 28.6-70.7), and neurological (28.8%; 95% CI 8.0-65.1) abnormalities. CONCLUSIONS: In a northern region of Tanzania, diabetes is an under-recognized health condition, despite the fact that many people either have diabetes or are at increased risk for developing diabetes. Most individuals were undiagnosed or untreated, and the prevalence of diabetes-associated complications was high. Public health efforts in this region will need to focus on reducing modifiable risk factors, which appear to include obesity, as well as early detection that includes increasing awareness. These findings highlight a growing urgency of diabetes prevention in this region as well as the need for treatment, including management of complications.

Reasons for poor follow-up of diabetic retinopathy patients after screening in Tanzania: a cross-sectional study.

BACKGROUND: Diabetes is an emerging public health problem in sub-Saharan Africa. Diabetic retinopathy is the commonest microvascular complication of diabetes and is a leading cause of blindness, mainly in adults of working age. Follow-up is crucial to the effective management of diabetic retinopathy, however, follow-up rates are often poor in sub-Saharan Africa. The aim of this study was to assess the proportion of patients not presenting for follow-up and the reasons for poor follow-up of diabetic patients after screening for retinopathy in Kilimanjaro Region of Tanzania. METHODS: All diabetic patients referred to a tertiary ophthalmology hospital after screening for retinopathy in 2012 were eligible for inclusion in the study. A randomly selected group of patients from the community-based diabetic retinopathy screening register were identified; among this group, follow-up was assessed. Interviews were conducted within this group to inform on the reasons for poor follow-up. RESULTS: Among the 203 patients interviewed in the study 50 patients (24.6 %) attended the recommended referral appointment and 153 (75.4 %) did not. Financial reasons were self-reported by 35.3 % of those who did not attend the follow-up appointment as the reason for non-attendance. Multiple logistic regression analysis showed that the patient report of the clarity of the referral process (p = 0.014) and the patient report of whether a healthcare worker told the patient that diabetic retinopathy could be treated (p = 0.005) were independently associated with attendance at a follow-up appointment. Income per month was not associated with attendance at a follow-up appointment on multivariate analysis. CONCLUSIONS: Financial factors are commonly cited as the reason for non-compliance with follow-up recommendations. However, the reasons for poor compliance are likely to be more complicated. This study highlights the importance of health system factors. Improving the clarity of the referral process and frequent reminders to patients that diabetic retinopathy can be treated are practical strategies that should be incorporated into screening programmes to increase attendance at subsequent follow-up appointments. The results from this study are applicable to other screening programmes as well as those for diabetic retinopathy.

Diabetic retinopathy in Tanzania: prevalence and risk factors at entry into a regional screening programme.

OBJECTIVE: The number of adults with diabetes in sub-Saharan Africa (SSA) is expected to almost double by 2035. This study investigated the prevalence of diabetic retinopathy (DR) and its risk factors at entry into a community-based screening programme. METHODS: All persons with diabetes screened for retinopathy at entry into a screening programme in Kilimanjaro Region, Tanzania between November 2010 and December 2014 were included. Fundus photographs were taken with a Topcon retinal camera following pupil dilation. Data were collected on BP, random blood sugar, duration of diabetes, BMI and visual acuity on entry. RESULTS: A total of 3187 persons were screened for DR. The prevalence of any DR was 27.9% (95%CI 26.4-29.5%) with background diabetic retinopathy (BDR), pre-proliferative diabetic retinopathy (PPDR) and proliferative diabetic retinopathy (PDR) having a prevalence of 19.1% (95% CI 17.7-20.4%), 6.0% (95%CI 5.2-6.8%) and 2.9% (95%CI 2.3-3.5%), respectively. Maculopathy was present in 16.1% (95%CI 14.8-17.4%) of participants. Multivariable logistic regression analysis for the presence of any DR found independent associations with duration of diabetes (P < 0.0001), systolic BP (P < 0.0001), random blood sugar (P < 0.0001) and attending a government hospital diabetic clinic (P = 0.0339). CONCLUSIONS: This study is the first to present data from a DR screening programme in SSA. The results will provide policymakers with data to aid planning of DR screening and treatment services in the African region. The study highlights the importance of managing comorbidities within DR screening programmes.

The Arclight Ophthalmoscope: A Reliable Low-Cost Alternative to the Standard Direct Ophthalmoscope.

Background. The Arclight ophthalmoscope is a low-cost alternative to standard direct ophthalmoscopes. This study compared the Arclight ophthalmoscope with the Heine K180 direct ophthalmoscope to evaluate its reliability in assessing the vertical cup disc ratio (VCDR) and its ease of use (EOU). Methods. Eight medical students used both the Arclight and the Heine ophthalmoscopes to examine the optic disc in 9 subjects. An EOU score was provided after every examination (a higher score indicating that the ophthalmoscope is easier to use). A consultant ophthalmologist provided the reference standard VCDR. Results. 288 examinations were performed. The number of examinations that yielded an estimation of the VCDR was significantly higher for the Arclight ophthalmoscope (125/144, 85%) compared to the Heine ophthalmoscope (88/144, 61%) (p < 0.001). The mean difference from the reference standard VCDR was similar for both instruments, with a mean of -0.078 (95% CI: -0.10 to -0.056) for the Arclight and -0.072 (95% CI: -0.097 to -0.046) for Heine (p = 0.69). The overall EOU score was significantly higher for the Arclight ophthalmoscope (p < 0.001). Conclusion. The Arclight ophthalmoscope performs as well as, and is easier to use than, a standard direct ophthalmoscope, suggesting it is a reliable, low-cost alternative.

Mass drug administration with praziquantel reduces the prevalence of Schistosoma mansoni and improves liver morbidity in untreated preschool children.

BACKGROUND: The aim of this study was to investigate the effects of mass drug administration on Schistosoma mansoni prevalence and associated liver morbidity in treated school-aged children and untreated preschool children. METHODS: In April 2008, parasitological (using the Kato-Katz method) and morbidity (determined by portal vein score) data were collected from 263 schoolchildren aged 6 and 7 years. The children had never received praziquantel. In March 2010, following two annual rounds of mass drug administration, 207 children aged 8 and 9 years old were examined to determine the effect of treatment. In addition, 158 untreated 6-year-olds were assessed to compare with the untreated children from 2008. RESULTS: Treatment significantly decreased the prevalence of S. mansoni and associated morbidity in the treated groups. The untreated preschool children also showed a significant decrease in the prevalence of S. mansoni, from 21.1% (2008) to 6.3% (2010) (p<0.001). The percentage of untreated schoolchildren with a normal portal vein score increased significantly from 57.8% (2008) to 70.3% (2010) (p=0.029). CONCLUSION: The significantly lower rates of S. mansoni and the decreased liver morbidity in untreated preschool children in 2010 suggest decreased environmental transmission rates and improved liver morbidity in untreated children following several rounds of mass drug administration.