Suprachoroidal hydrogel systems for posterior ocular therapy: Design principles, therapeutic applications, and translational challenges

Suprachoroidal delivery offers a minimally invasive route for targeting the choroid and retina, while reducing complications related to conventional ocular delivery methods. This review focuses on hydrogels engineered for the suprachoroidal space (SCS) as advanced materials platforms for next-generation posterior ocular therapy. We outline key hydrogel design principles in the context of SCS anatomy and biomechanics and highlight how crosslinking chemistry and material properties can be tuned for specific therapeutic goals. Promising applications of SCS hydrogel systems are discussed, including (i) reduction of intraocular pressure (IOP), (ii) swelling-assisted targeting of drug particles toward the posterior eye, (iii) prolonged delivery of biologics, such as anti-vascular endothelial growth factor (VEGF) agents, (iv) minimally invasive support of cell transplantation, and (v) hydrogel-forming microneedles (HFMNs) for assessing SCS. We also discuss key translational considerations such as preclinical to clinical translation, biocompatibility, injectability, storage stability, sterilization, manufacturing, and scalability alongside future development directions. Taken together, this review introduces SCS-targeted hydrogels as a distinct class of minimally invasive and clinically relevant materials for the treatment of posterior eye diseases.