Sutureless, ultra-swollen hydrogel scleral buckle for microinvasive treatment of rhegmatogenous retinal detachment

Rhegmatogenous retinal detachment (RRD) is an ophthalmic emergency requiring prompt treatment to prevent irreversible vision loss or blindness. Although scleral buckling is a commonly used external surgical procedure for RRD, it poses significant challenges, including suture-related complications and implant-associated adverse effects (e.g., foreign-body reaction, scleral indentation, and conjunctival exposure of conventional silicone implants). Herein, we developed an ultra-swollen hydrogel as an alternative scleral buckle to address these limitations. Specifically, this hydrogel was formulated with N-vinylpyrrolidone (NVP) and methacryloxyethyltrimethylammonium chloride (DMC) as hydrophilic components, reinforced with methyl methacrylate (MMA), and crosslinked with N, N'-bis(acryloyl)cystamine (BCA). This formulation enables the hydrogel to be implanted in a dehydrated, compact form through a small incision and subsequently swell in situ to 830% of its original volume for scleral buckling treatment of RRD. Despite this high swelling ratio, the densely crosslinked network (based on BCA crosslinker) preserves sufficient mechanical integrity, and the swollen hydrogel tightly conforms to the extrascleral surface, generating sufficient friction to eliminate the need for sutures and thus avoiding suture-related complications associated with conventional silicone implants. In vitro assessments demonstrated excellent biocompatibility, with no significant cytotoxicity or adverse effects on cell proliferation. Building on this in vitro safety profile, in vivo studies confirmed that the hydrogel provided sufficient external support to facilitate retinal reattachment without inducing significant rejection responses. In summary, this ultra-swollen hydrogel represents a novel and promising therapeutic strategy for RRD, with significant potential for clinical translation.