Title: Delivery Models of Diabetic Retinopathy Services in Low- and Middle-Income Countries: A Scoping Review

Summary: This scoping review maps DR service delivery models implemented in LMICs and describes the available evidence on their effectiveness. We included 129 reports from 58 LMICs.

Key Findings:

• 81.9% of DR screening was integrated within routine diabetes/NCD services, mostly at primary care level.
• Task-sharing and task-shifting were common, supported by fundus photography (76%), telemedicine (35%), and AI-assisted grading (10%).
• Treatment remains highly centralised at tertiary facilities and is delivered almost exclusively by ophthalmologists.
• Referral adherence and long-term treatment outcomes are poorly reported.
• Organised screening combined with treatment was consistently cost-effective (e.g. US$400/QALY in Malawi, US$248/QALY in India).

Conclusions: DR services in LMICs show increasing integration with diabetes care and adoption of digital technologies, but treatment is centralised and effectiveness evidence on complete end-to-end models remains limited.

Keywords: Diabetic retinopathy, screening, service delivery models, LMICs, task-sharing, telemedicine, artificial intelligence, cost-effectiveness