Evaluating the feasibility and safety of a self-crosslinked hyaluronic acid hydrogel for experimental retinal detachment repair.

Hyaluronic acid (HA), a glycosaminoglycan, maintains the gel consistency of the vitreous humors by retaining water. It hydrates the vitreous and prevents it from collapsing and is a major component of native vitreous. HA hydrogel, renowned for its high biocompatibility and biodegradability, has great potential for the development of an artificial vitreous. In this study, we evaluated a self-crosslinking HA hydrogel using a copolymer of aldehyde HA (HA-CHO) and amide HA (HA-NH2) as a biodegradable vitreous substitute for the surgical treatment of rhegmatogenous retinal detachment (RRD). Our study showed that the HA hydrogel could be easily injected into rabbit eyes through a 25G needle, where it rapidly formed a gel network. The key parameters of this hydrogel, including transmittance, refractive index and modulus, are suitable for post-vitrectomy filling. In vitro cytotoxicity assays demonstrated that the hydrogel exhibited excellent cell compatibility without inducing significant cytotoxicity. During the 60-day follow-up period for the treatment of experimental rhegmatogenous retinal detachment in rabbits, the HA hydrogel showed a good intraocular compatibility and maintained normal intraocular pressure (IOP), with no complications such as retinal redetachment or endophthalmitis in our study. Histopathology and retinal electrophysiology showed no tissue damage or retinal dysfunction in the HA hydrogel group. In addition, no recurrent retinal detachment occurred and the hydrogel biodegraded within a short time after surgery. Therefore, this chemically cross-linked hydrogel could be one of the options for a biodegradable intraocular filler in the vitreous cavity after retinal detachment surgery.