Background <p>Diabetic retinopathy is a major microvascular complication of type 2 diabetes mellitus and remains a leading cause of preventable visual impairment worldwide. Understanding the time to onset of diabetic retinopathy and its prognostic factors is essential to optimise screening strategies and guide early intervention. This study aimed to determine the time to development of diabetic retinopathy and identify its associated prognostic factors among adults with type 2 diabetes mellitus in Johor, Malaysia.</p> Methods <p>We conducted a retrospective cohort study using secondary data from the National Diabetes Registry in Johor, Malaysia. Adults aged ≥ 18 years with type 2 diabetes mellitus who had no documented diabetic retinopathy DR at cohort entry were included. Cohort entry was defined as the first eligible National Diabetes Registry registration/assessment date between 1 January 2015 and 31 December 2019. Participants were followed until first documented diabetic retinopathy, death, loss to follow-up, transfer out, or 31 December 2019, whichever occurred first. Baseline sociodemographic, clinical, treatment-related and complication variables were evaluated. Kaplan–Meier methods, Log-rank test, and Cox regression analyses were used to evaluate time to first documented diabetic retinopathy and its prognostic factors.</p> Results <p>Of 50,457 registry records initially identified, 1,056 duplicate records were removed. After excluding 1,448 records with incomplete eligibility, outcome or key baseline information, 47,953 participants were included in the original analytic dataset. Of these, 6,402 (13.3%) had a diabetic retinopathy diagnosis recorded in the registry and 41,551 (86.7%) were censored. Following verification of temporal eligibility and exclusion of 6,401 prevalent diabetic retinopathy records recorded before or at cohort entry, 41,552 participants contributed 64,551.7 person-years of follow-up, during which one incident diabetic retinopathy event occurred. Median follow-up estimated using the reverse Kaplan–Meier method was 6.1 months (IQR 5.3–29.0; range 3.2–113.4 months). duration of diabetes greater than 10 years (AHR = 1.96, 95% CI: 1.79–2.14), hypertension (AHR = 1.20, 95% CI: 1.10–1.31), dyslipidaemia (AHR = 1.25, 95% CI: 1.16–1.34), high waist circumference (AHR = 1.08, 95% CI: 1.02–1.14), positive urine protein (AHR = 1.09, 95% CI: 1.04–1.15), poor glycaemic control (AHR = 1.11, 95% CI: 1.03–1.20), and complications such as nephropathy (AHR = 1.78, 95% CI: 1.69–1.88) and diabetic foot ulcer (AHR = 1.92, 95% CI: 1.67–2.20) were independently associated with an increased risk of diabetic retinopathy.</p> Conclusions <p>Diabetic retinopathy develops within a relatively short duration following type 2 diabetes mellitus diagnosis and is influenced by a combination of metabolic, clinical, and complication-related factors. Early risk stratification and integrated management of modifiable risk factors are essential to delay the onset of diabetic retinopathy. These findings provide important real-world evidence to support targeted screening and public health strategies in Malaysia.</p>