Injectable hyaluronic acid hydrogels for the treatment of ocular diseases: A review.

Globally, an increasing number of individuals suffer from ocular diseases, including dry eye syndrome, corneal injuries, and age-related macular degeneration (AMD), ultimately leading to visual impairment or complete blindness. The complex anatomy and physiological barriers of the eye limit the efficacy of conventional therapies such as eye drops and intraocular injections, while also posing challenges including frequent dosing requirements and inflammatory risks. Injectable hyaluronic acid (HA) hydrogels present a promising strategy to address the limitations of current ocular therapies, owing to their excellent biocompatibility, tunable physicochemical properties (including optical transparency and mechanical modulus), and sustained drug release capabilities. Recent research continues to explore the potential of functionalized injectable HA hydrogels to advance ophthalmic treatment paradigms. This review summarizes recent advances in the chemical modification and crosslinking strategies of HA, as well as innovative design concepts for functionalized injectable HA hydrogels in treating ocular disorders such as corneal injuries and AMD. Injectable HA hydrogels show considerable promise for improving therapeutic outcomes, reducing treatment frequency and side effects, lowering healthcare costs, and enhancing patient compliance. This review aims to provide theoretical support for the future development of emerging HA hydrogel-based platforms for ocular care.