Feasibility and acceptance of artificial intelligence-based diabetic retinopathy screening in Rwanda.

BACKGROUND: Evidence on the practical application of artificial intelligence (AI)-based diabetic retinopathy (DR) screening is needed. METHODS: Consented participants were screened for DR using retinal imaging with AI interpretation from March 2021 to June 2021 at four diabetes clinics in Rwanda. Additionally, images were graded by a UK National Health System-certified retinal image grader. DR grades based on the International Classification of Diabetic Retinopathy with a grade of 2.0 or higher were considered referable. The AI system was designed to detect optic nerve and macular anomalies outside of DR. A vertical cup to disc ratio of 0.7 and higher and/or macular anomalies recognised at a cut-off of 60% and higher were also considered referable by AI. RESULTS: Among 827 participants (59.6% women (n=493)) screened by AI, 33.2% (n=275) were referred for follow-up. Satisfaction with AI screening was high (99.5%, n=823), and 63.7% of participants (n=527) preferred AI over human grading. Compared with human grading, the sensitivity of the AI for referable DR was 92% (95% CI 0.863%, 0.968%), with a specificity of 85% (95% CI 0.751%, 0.882%). Of the participants referred by AI: 88 (32.0%) were for DR only, 109 (39.6%) for DR and an anomaly, 65 (23.6%) for an anomaly only and 13 (4.73%) for other reasons. Adherence to referrals was highest for those referred for DR at 53.4%. CONCLUSION: DR screening using AI led to accurate referrals from diabetes clinics in Rwanda and high rates of participant satisfaction, suggesting AI screening for DR is practical and acceptable.

Use of the World Health Organization primary eye care protocol to investigate the ocular health status of school children in Rwanda.

PURPOSE: To assess the ocular health status of primary and secondary schoolchildren in Rwanda and to explore the use of the World Health Organization (WHO) primary eye care screening protocol. METHODS: This was a cross-sectional population-based study across 19 schools in Rwanda. Initial screening was carried out using the WHO screening protocol, whereby visual acuity was measured using a tumbling E Snellen chart (6/60 and 6/12). Abnormal ocular features were identified using a flashlight and history against a checklist. All children with abnormal screening were referred to an on-site ophthalmic clinic for full examination. Those who could not be treated on-site were referred to an ophthalmologist at a hospital for specialist care. RESULTS: A total of 24,892 children underwent ocular health screening. Of those, 1,865 (7.5%) failed the primary screening; 658 (2.6%) were false positives (35.3% of those who failed screening), and 1,207 (4.8%) true positives. The most frequently observed ocular diagnoses were allergic conjunctivitis (3.11%) and strabismus (0.26%). Refractive error was very rare (0.18%). CONCLUSIONS: The WHO primary eye care curriculum provides existing health personnel with an approach to school-based vision screening that uses a standardized checklist and low-cost resources. In our study cohort, results indicated a low frequency of refractive error; the overwhelming majority of ocular problems could be identified on visual inspection.

Impact of Artificial Intelligence Assessment of Diabetic Retinopathy on Referral Service Uptake in a Low-Resource Setting: The RAIDERS Randomized Trial.

Purpose: This trial was designed to determine if artificial intelligence (AI)-supported diabetic retinopathy (DR) screening improved referral uptake in Rwanda. Design: The Rwanda Artificial Intelligence for Diabetic Retinopathy Screening (RAIDERS) study was an investigator-masked, parallel-group randomized controlled trial. Participants: Patients ≥ 18 years of age with known diabetes who required referral for DR based on AI interpretation. Methods: The RAIDERS study screened for DR using retinal imaging with AI interpretation implemented at 4 facilities from March 2021 through July 2021. Eligible participants were assigned randomly (1:1) to immediate feedback of AI grading (intervention) or communication of referral advice after human grading was completed 3 to 5 days after the initial screening (control). Main Outcome Measures: Difference between study groups in the rate of presentation for referral services within 30 days of being informed of the need for a referral visit. Results: Of the 823 clinic patients who met inclusion criteria, 275 participants (33.4%) showed positive findings for referable DR based on AI screening and were randomized for inclusion in the trial. Study participants (mean age, 50.7 years; 58.2% women) were randomized to the intervention (n = 136 [49.5%]) or control (n = 139 [50.5%]) groups. No significant intergroup differences were found at baseline, and main outcome data were available for analyses for 100% of participants. Referral adherence was statistically significantly higher in the intervention group (70/136 [51.5%]) versus the control group (55/139 [39.6%]; P = 0.048), a 30.1% increase. Older age (odds ratio [OR], 1.04; 95% confidence interval [CI], 1.02-1.05; P < 0.0001), male sex (OR, 2.07; 95% CI, 1.22-3.51; P = 0.007), rural residence (OR, 1.79; 95% CI, 1.07-3.01; P = 0.027), and intervention group (OR, 1.74; 95% CI, 1.05-2.88; P = 0.031) were statistically significantly associated with acceptance of referral in multivariate analyses. Conclusions: Immediate feedback on referral status based on AI-supported screening was associated with statistically significantly higher referral adherence compared with delayed communications of results from human graders. These results provide evidence for an important benefit of AI screening in promoting adherence to prescribed treatment for diabetic eye care in sub-Saharan Africa.

Incidence of Visually Impairing Cataracts Among Older Adults in Kenya.

Importance: Half of all the cases of blindness worldwide are associated with cataract. Cataract disproportionately affects people living in low- and middle-income countries and persons of African descent. Objective: To estimate the 6-year cumulative incidence of visually impairing cataract in adult participants in the Nakuru Eye Disease Cohort Study in Kenya. Design, Setting, and Participants: This secondary analysis of the Nakuru Eye Disease Cohort Study was conducted from February 2016 to April 2016. This cohort comprised citizens of Nakuru, Kenya, aged 50 years or older who consented to participate in the initial or baseline survey from January 2007 to November 2008, as well as the follow-up conducted from January 2013 to March 2014. All participants at baseline (n = 4364) and follow-up (n = 2159) underwent ophthalmic examination. Main Outcomes and Measures: Six-year cumulative incidence of visually impairing cataract, risk factors of incidence, population estimates, and required cataract surgical rates to manage incident visually impairing cataract. Results: In total, 4364 individuals (with a mean [SD] age of 63.4 [10.5] years and with 2275 women [52.1%]) had complete eye examinations at baseline, and 2159 participants (with a mean [SD] age of 62.5 [9.3] years and with 1140 men [52.8%]) were followed up 6 years later. The 6-year cumulative incidence of visually significant cataract in either eye was 251.9 per 1000 (95% CI, 228.5-276.8), with an increase with age from 128.9 (95% CI, 107.9-153.2) per 1000 for the group aged 50 to 59 years to 624.5 (95% CI, 493.1-739.9) per 1000 for the group aged 80 years or older. This equated to an annual incidence of visually significant cataract of 45.0 per 1000 people aged 50 years or older. Multivariable analysis showed alcohol consumption (risk ratio [RR], 1.4; 95% CI, 1.1-1.8), diabetes (RR, 1.7; 95% CI, 1.3-2.3), educational level, and increasing age (RR, 3.8; 95% CI, 2.6-5.5 for those aged ≥80 years) were associated with incident visually impairing cataract. Extrapolations to all people aged 50 years or older in Kenya indicated that 148 280 (95% CI, 134 510-162 950) individuals might develop new visually impairing cataract in either eye (visual acuity <6/18 in the worse-seeing eye) and that 9540 (95% CI, 6610-13 750) might become cataract blind in both eyes (visual acuity <3/60 in better-seeing eye). Conclusions and Relevance: Adults in Kenya appeared to have a high incidence of visually impairing cataract, making cataract a priority for blindness prevention programs in the region; surgical interventions and awareness of these services are also required.

Improving eye care in Rwanda.

PROBLEM: Visual impairment affects nearly 285 million people worldwide. Although there has been much progress in combating the burden of visual impairment through initiatives such as VISION 2020, barriers to progress, especially in African countries, remain high. APPROACH: The Rwandan Ministry of Health has formed partnerships with several nongovernmental organizations and has worked to integrate their efforts to prevent and treat visual impairment, including presbyopia. LOCAL SETTING: Rwanda, an eastern African country of approximately 11 million people. RELEVANT CHANGES: The Rwandan Ministry of Health developed a single national plan that allows key partners in vision care to coordinate more effectively in measuring eye disease, developing eye care infrastructure, building capacity, controlling disease, and delivering and evaluating services. LESSONS LEARNT: Collaboration between stakeholders under a single national plan has ensured that resources and efforts are complementary, optimizing the ability to provide eye care. Improved access to primary eye care and insurance coverage has increased demand for services at secondary and tertiary levels. A comprehensive strategy that includes prevention as well as a supply chain for glasses and lenses is needed.

Vernal keratoconjunctivitis in school children in Rwanda: clinical presentation, impact on school attendance, and access to medical care.

OBJECTIVE: We sought to describe the clinical presentation, effect on visual acuity, impact on school attendance, and access to appropriate eye care in children with vernal keratoconjunctivitis (VKC) in Rwanda (Central Africa). DESIGN: Case-control study nested within a cross-sectional survey. PARTICIPANTS: We examined 3041 children; 121 had VKC. METHODS: Primary schools were randomly selected and children were interviewed using a questionnaire on VKC-related symptoms. Data on health-seeking behavior and school attendance were recorded. Children received a full eye examination, including visual acuity using a LogMar E Chart. MAIN OUTCOME MEASURES: Description of the clinical findings, unaided visual acuity, prior attendance for medical eye care, and the impact of VKC on school attendance. RESULTS: Of the 121 children with VKC, 119 (98.4%) had only limbal disease. Ocular itching (n = 101; 83.5%) was the predominant symptom and this was seasonal in 66 children (65.4%), constant but with variable intensity in 18 (17.8%), and constant with constant intensity in 17 children (16.8%). Children with VKC were >6 times more likely to have corneal astigmatism >2 diopters in their worse eye (odds ratio [OR], 6.31; 95% confidence interval [CI], 3.26-12.26; P<0.001) than controls. Eight affected eyes had astigmatism >4 diopters or irregular astigmatism incompatible with autokeratometry. Although 4 eyes (1.7%) had uncorrected low vision from VKC-induced corneal astigmatism or keratoconus, only 1 child was visually impaired in both eyes. School nonattendance for an ocular reason during the last 3 months was 5 times more likely in children with VKC (n = 44; 36.4%) than among those without (n = 297; 10.2%; OR, 5.04; 95% CI, 3.40-7.47; P < 0.001). Repeating a school year or having ever dropped out of school was not more common among children with VKC than those without. Medical eye care had been sought by 54 (44.6%) children with VKC. CONCLUSIONS: This survey of prevalence and treatment of VKC in an African community adds to the argument for better primary eye care, including a safe topical medication. Long-term follow-up of this cohort is required to ascertain the overall risk of sight-threatening complications.

Topical ciclosporin in the treatment of vernal keratoconjunctivitis in Rwanda, Central Africa: a prospective, randomised, double-masked, controlled clinical trial.

AIM: To compare the short-term efficiency and safety of topical ciclosporin A (CsA) 2% with dexamethasone 0.1% in the treatment of predominantly limbal vernal keratoconjunctivitis (VKC) in Rwanda, Central Africa. METHODS: Consecutive patients with VKC were randomised in a prospective, double-masked, clinical trial to receive either topical CsA 2% dissolved in olive oil vehicle or dexamethasone 0.1% drops for 4 weeks. Both groups then received sodium chromoglycate 2% drops for maintenance therapy for a further 4 weeks. The primary outcome was the reduction in composite score for VKC-related symptoms and signs at 4 weeks. Secondary outcomes included side effects, best-corrected visual acuity, comfort rating of the trial drops during 4 weeks' test medication and relapse rate thereafter. RESULTS: The 366 participants recruited had the limbal (91.5%) or mixed form of VKC. At the end of the 4-week treatment period, the composite score had decreased significantly (p<0.001) from baseline without any significant difference between CsA and dexamethasone (p=0.20). There were no severe adverse reactions, but CsA drops caused more stinging than the oil placebo and dexamethasone (p<0.001). In both treatment groups, the visual acuity had improved at 4 weeks compared with baseline (p<0.001) with no significant difference between the treatment arms. The relapse rate following cessation of the trial treatments was similar (p=0.84) in both groups. CONCLUSION: There is no significant difference between the efficiency of topical CsA 2% and dexamethasone 0.1% for the management of acute VKC in Central Africa, but tolerance needs to be improved.

Vernal keratoconjunctivitis in school children in Rwanda and its association with socio-economic status: a population-based survey.

Vernal keratoconjunctivitis (VKC) is an allergic eye disease and an important cause of hospital referral among children in Africa and Asia. Hospital-based studies have suggested a role for parasites in its pathogenesis. To determine the prevalence and risk factors for VKC in Central Africa, we conducted a nested population-based case control study in Rwanda, involving randomly selected primary schools from different environments (rural/urban) and climate. A prevalence of VKC of 4.0% (95% confidence interval 3.3-4.7%) was found among 3,041 children studied (participation rate 94.7%). The intestinal parasitic burden was not related to VKC. Besides hot dry climate (odds ratio [OR] = 1.5, P = 0.05) and male gender (OR = 1.7, P = 0.005), multivariate analysis identified higher economic status as a risk for VKC (OR = 1.4, P = 0.005). The effect on VKC of higher economic status appears not to act through differences in parasitic intestinal load.

Estimating incidence of vision-reducing cataract in Africa: a new model with implications for program targets.

OBJECTIVE: To estimate the incidence of vision-reducing cataract in sub-Saharan Africa and use these data to calculate cataract surgical rates (CSR) needed to eliminate blindness and visual impairment due to cataract. METHODS: Using data from recent population-based, standardized, rapid-assessment surveys, we calculated the age-specific prevalence of cataract (including operated and unoperated eyes) from surveys in 7 "districts" across Africa. This was done at 3 levels of visual acuity. Then we used the age-specific prevalence data to develop a model to estimate age-specific incidence at different visual acuities, taking into account differences in mortality rates between those with cataract compared with those without. The model included development of opacity in the first eye and second eye of people older than 50 years. The incidence data were used to calculate target cataract surgical rates. RESULTS: Incidence and CSR needs varied significantly in different sites and were lower in some than expected. Cataract surgical rates may depend on genetic, environmental, or cultural variations and will vary with population structure, which is not uniform across Africa. CONCLUSION: Africa should not be viewed as homogeneous in terms of cataract incidence or CSR needed. These CSR calculations should be useful for more appropriate planning of human resources and service delivery on the continent. The methodology can be applied to other population-based data as they become available to determine appropriate CSR targets.

Rapid assessment of avoidable blindness in Western Rwanda: blindness in a postconflict setting.

BACKGROUND: The World Health Organization estimates that there were 37 million blind people in 2002 and that the prevalence of blindness was 9% among adults in Africa aged 50 years or older. Recent surveys indicate that this figure may be overestimated, while a survey from southern Sudan suggested that postconflict areas are particularly vulnerable to blindness. The aim of this study was to conduct a Rapid Assessment for Avoidable Blindness to estimate the magnitude and causes of visual impairment in people aged > or = 50 y in the postconflict area of the Western Province of Rwanda, which includes one-quarter of the population of Rwanda. METHODS AND FINDINGS: Clusters of 50 people aged > or = 50 y were selected through probability proportionate to size sampling. Households within clusters were selected through compact segment sampling. Visual acuity (VA) was measured with a tumbling "E" chart, and those with VA below 6/18 in either eye were examined by an ophthalmologist. The teams examined 2,206 people (response rate 98.0%). The unadjusted prevalence of bilateral blindness was 1.8% (95% confidence interval [CI] 1.2%-2.4%), 1.3% (0.8%-1.7%) for severe visual impairment, and 5.3% (4.2%-6.4%) for visual impairment. Most bilateral blindness (65%) was due to cataract. Overall, the vast majority of cases of blindness (80.0%), severe visual impairment (67.9%), and visual impairment (87.2%) were avoidable (i.e.. due to cataract, refractive error, aphakia, trachoma, or corneal scar). The cataract surgical coverage was moderate; 47% of people with bilateral cataract blindness (VA < 3/60) had undergone surgery. Of the 29 eyes that had undergone cataract surgery, nine (31%) had a best-corrected poor outcome (i.e., VA < 6/60). Extrapolating these estimates to Rwanda's Western Province, among the people aged 50 years or above 2,565 are expected to be blind, 1,824 to have severe visual impairment, and 8,055 to have visual impairment. CONCLUSIONS: The prevalence of blindness and visual impairment in this postconflict area in the Western Province of Rwanda was far lower than expected. Most of the cases of blindness and visual impairment remain avoidable, however, suggesting that the implementation of an effective eye care service could reduce the prevalence further.