Real-world evaluation of smartphone-based artificial intelligence to screen for diabetic retinopathy in Dominica: a clinical validation study.

OBJECTIVE: Several artificial intelligence (AI) systems for diabetic retinopathy screening have been validated but there is limited evidence on their performance in real-world settings. This study aimed to assess the performance of an AI software deployed within the diabetic retinopathy screening programme in Dominica. METHODS AND ANALYSIS: We conducted a prospective, cross-sectional clinical validation study. Patients with diabetes aged 18 years and above attending the diabetic retinopathy screening in primary care facilities in Dominica from 5 June to 3 July 2021 were enrolled.Grading was done at the point of care by the field grader, followed by counselling and referral to the eye clinic. Images were then graded by an AI system. Sensitivity, specificity with 95% CIs and area under the curve (AUC) were calculated for comparing the AI to field grader as gold standard. RESULTS: A total of 587 participants were screened. The AI had a sensitivity and specificity for detecting referable diabetic retinopathy of 77.5% and 91.5% compared with the grader, for all participants, including ungradable images. The AUC was 0.8455. Excluding 52 participants deemed ungradable by the grader, the AI had a sensitivity and specificity of 81.4% and 91.5%, with an AUC of 0.9648. CONCLUSION: This study provides evidence that AI has the potential to be deployed to assist a diabetic screening programme in a middle-income real-world setting and perform with reasonable accuracy compared with a specialist grader.

Cataract in Latin America: findings from nine recent surveys / La catarata en América Latina: resultados de nueve encuestas recientes

OBJECTIVES: To review recent data on blindness and low vision due to cataract in Latin America. METHODS: Presentation of findings from population-based prevalence surveys conducted between 1999 and 2006 in nine Latin American countries covering 30 544 people aged 50 years and older. RESULTS: Prevalence of cataract blindness in people 50 years and older ranged from 0.5 percent in Buenos Aires to 2.3 percent in four provinces of Guatemala. Low vision from cataract ranged from 0.9 percent in Buenos Aires to 10.7 percent in Piura and Tumbes Districts in Peru. Cataract surgical coverage (CSC) was good in Campinas, Brazil; low in Paraguay, Peru, and Guatemala; and moderate in the other areas. Good visual outcome after cataract surgery nearly conformed to World Health Organization (WHO) guidelines in Buenos Aires (more than 80 percent of operated eyes able to see 20/60 or better), but ranged from 60 percent to 79 percent in most of the other settings, and was less than 60 percent in Guatemala and Peru. "Unaware that treatment is possible," "contraindications," "cannot afford," and "fear of operation" were the most common explanations for failure to come forward for surgery. CONCLUSIONS: In Campinas, Brazil, cataract is fairly well controlled. In Buenos Aires, the visual outcomes after cataract surgery nearly meet WHO standards. In most countries in Latin America, however, cataract intervention needs to be intensified and visual outcome improved. Reducing the costs of cataract surgery and providing effective health education and adequate program management are essential to combat the expected increase in visual impairment due to cataract in the region.

OBJETIVO: Hacer una revisión de los datos recientes sobre ceguera y visión reducida por catarata en América Latina. MÉTODO: Presentación de los resultados de estudios de prevalencia de base poblacional realizados entre 1999 y 2006 en nueve países latinoamericanos, que abarcaron 30 544 personas de 50 años o más. RESULTADOS: La prevalencia de ceguera por catarata en personas de 50 años o más estuvo entre 0,5 por ciento en Buenos Aires, Argentina, y 2,3 por ciento en cuatro provincias de Guatemala. La visión reducida por catarata varió entre 0,9 por ciento en Buenos Aires y 10,7 por ciento en los distritos de Piura y Tumbes, Perú. La cobertura de cirugía de catarata fue buena en Campinas, Brasil; baja en Paraguay, Perú y Guatemala; y media en el resto de las áreas. Los resultados positivos de la cirugía de catarata estuvieron muy cerca de los estándares de la Organización Mundial de la Salud (OMS) en Buenos Aires (más de 80 por ciento de los ojos operados con visión de 20/60 o mejor), pero varió entre 60 por ciento y 79 por ciento en la mayoría de los otros lugares y fue inferior a 60 por ciento en Guatemala y Perú. Las explicaciones expuestas más frecuentemente para no someterse a esta operación fueron "no saber que el tratamiento es posible", "contraindicaciones", "no poder pagarlo" y "temor a la operación". CONCLUSIONES: En Campinas, la catarata está bastante bien controlada. En Buenos Aires, la visión después de la cirugía de catarata se acerca a los estándares de la OMS. No obstante, en la mayoría de los países de América Latina las intervenciones contra la catarata deben intensificarse y sus resultados deben mejorar. Es esencial reducir el costo de la cirugía de catarata y brindar una educación sanitaria eficaz y programas adecuados para combatir el esperado aumento en los trastornos de la visión por catarata en la Región.

Cataract blindness in Paraguay--results of a national survey.

PURPOSE: To estimate the burden of visual loss and blindness due to cataract in people aged 50 years and over in Paraguay. METHODS: Forty clusters of 60 persons each who were 50 years and older (2400 eligible persons) were selected by systematic random sampling from the entire population of Paraguay. A total of 2136 persons were examined (89% coverage). RESULTS: For the population 50 years and over, the age- and gender-adjusted prevalence of bilateral blindness (VA < 3/60 with available correction) was 3.14% (95% CI: 2.2-4.4). The adjusted prevalence of bilateral cataract blindness (VA < 3/60) was 2.01% (95% CI: 1.3-3.0), making cataract the major cause of bilateral blindness in this age group (64%). The adjusted prevalence of bilateral severe visual impairment (VA < 6/60 with available correction) was 5.17% (95% CI: 3.9-6.7) and the adjusted prevalence of severe visual impairment due to bilateral cataract (VA < 6/60) was 3.09% (95% CI: 2.2-4.3). The cataract surgical coverage (persons) was 44% for bilaterally blind persons with VA < 3/60; 36% for persons with bilateral VA < 6/60; and 28% for any eye with VA < 6/60 due to cataract. With IOL implantation, 77% of the operated eyes could see 6/18, against 46% of the non-IOLs (p < 0.005), a significant better outcome. CONCLUSION: There is a need to increase the cataract surgical coverage in Paraguay. The number of eye surgeons is adequate but the accessibility of cataract surgical services in rural areas and the affordability of surgery to large sections of society are major constraints.