Recent Advances in Ophthalmic Drug Delivery: Current Status and Future Perspectives.

Abstract

Vision impairment is a significant global health issue, affecting people of all ages and notably influencing quality of life. One of the major challenges in treating eye diseases is the effective delivery of drugs, as the eye possesses unique anatomical and physiological barriers. Structures such as tear drainage, the tightly packed corneal epithelium, and the blood‑ocular barriers often hinder medications from reaching therapeutic concentrations. Conventional treatments such as eye drops, ointments, and oral medications frequently exhibit poor bioavailability and limited penetration into target sites, particularly in posterior segment diseases. This often leads to minimal therapeutic relief or requires frequent dosing, which can compromise patient comfort and adherence. Recent advancements in drug delivery technologies have shown promise in enhancing therapeutic efficacy, prolonging drug retention, and improving patient compliance. This review highlights the critical barriers in ocular drug delivery and emphasizes the urgent need for innovative strategies to address them. It comprehensively discusses emerging technologies, including nanotechnology, nanocomposite contact lenses, intraocular implants, microneedles, and gene therapy, focusing on their ability to improve drug delivery and retention in ocular tissues. Moreover, challenges associated with these innovative systems, including safety concerns, regulatory hurdles, and manufacturing constraints, are explored. Subsequently, proposed future directions include smart delivery systems, precision medicine, and efforts to ensure equitable access worldwide. Overall, this review provides an integrated perspective on the current advances and future hope of ocular drug delivery technologies for patients with chronic or vision‑threatening eye diseases.