##article.abstract##
<p><em><strong>Objective:</strong></em>To determine the prevalence of diabetic retinopathy and diabetic macular edema by means of retinography in patients diagnosed with Type 2 diabetes mellitus according to time of evolution and degree of vision loss with and without refractive correction.<em><strong>Method:</strong> </em>A descriptive cross-sectional study of 150 patients with Type 2 diabetes mellitus assessed in optometry in various health centers from the Sanitary Jurisdiction of Tlalpan, Health Services of Mexico City.<em><strong>Results:</strong></em> 150 patients (70% women, 30% men) aged 60 (+/– 7.77) were diagnosed with Type 2 diabetes mellitus, 52% of them with an evolution of 12.09 years (+/– 3.48). Of the total number of patients, 72.33% had retinopathy and/or diabetic macular edema lesions. The average visual acuity improved from 0.62 (+/– 0.48) to 0.37 (+/– 0.38) with refractive correction, absolute disability decreased by –18.76% and null or slight disability increased by 31.31%. Of the total population, 75.5% remained under monitoring in primary care, and 24.5% were referred to tertiary care in ophthalmology.<em><strong>Conclusion:</strong></em> The strategic opportunity to combat vision loss due to retinopathy and diabetic macular edema is found in its timely detection by health personnel trained in scrutiny and control at the primary care level, which would represent a decreased hospital load in tertiary care, thereby reducing costs for the health systems, as well as cost-efficiency for the years of sight gained and optimization of the patient’s global vision.</p>