Diabetic retinopathy (DR) is a leading cause of vision impairment and blindness in diabetic patients, with the global prevalence of the disease continuing to rise. Despite the availability of several treatment modalities, managing DR remains challenging due to limitations in the efficiency of drug delivery methods and patient compliance. This review aims to provide a comprehensive overview of traditional ocular drug delivery systems, including topical, intraocular, and systemic methods, highlighting their mechanisms, benefits, and limitations. Recent advancements in drug delivery systems, such as nanoparticlebased platforms, microneedle arrays, implantable devices, and smart drug delivery systems, are explored with a focus on their potential to overcome current challenges. Key clinical trials and research studies are discussed to evaluate the efficacy, safety, and outcomes of these advanced systems. Furthermore, the review examines technical, regulatory, and patient-related challenges while speculating on future directions, including the integration of emerging technologies and the development of more effective, patient-friendly treatment options for DR.

Keywords: Diabetic retinopathy, Ocular drug delivery, Nanoparticle systems, Microneedle arrays, Sustained-release systems, Smart drug delivery, Clinical trials, Advanced therapies.