Diabetic retinopathy is a leading cause of vision loss among urban youth in Nairobi slums, where access to healthcare and diagnostic resources are limited. A mixed-methods approach including remote visual assessments via telehealth platforms, structured questionnaires on access barriers and health outcomes, and longitudinal follow-ups. Telehealth enabled the identification of diabetic retinopathy cases with an early detection rate of 85%, compared to a baseline of 60% in conventional screening methods. Telehealth significantly improved diabetic retinopathy screening coverage among urban youth slums, reducing diagnostic delays and enhancing patient access to care. Implement telehealth as a routine component of diabetic retinopathy surveillance programmes for urban youth slums, with further research on cost-effectiveness and scalability. Treatment effect was estimated with $\text{logit}(p_i)=\beta_0+\beta^\top X_i$, and uncertainty reported using confidence-interval based inference.