Rhegmatogenous retinal detachment (RRD) is caused by one or more full-thickness retinal breaks. The current RRD treatments have several drawbacks. Chitosan is one of the most commonly used natural polymers for wound healing and has been demonstrated to be biodegradable, biocompatible, non-toxic, bioadhesive, and bioactive. This study aimed to determine the reliability and effectiveness of chitosan for sealing retinal breaks in rabbits.Eighteen blue purple rabbits were randomly divided into three groups: chitosan (n = 6), RRD (n = 6), and control (n = 6). The RRD model was established using vitrectomy, making retinal holes, and subretinal fluid injection in the RRD and chitosan groups. One week after the establishment of the model, chitosan was applied within the range of the holes in the chitosan group, and the vitreous body was filled with perfusion fluid. Except the chitosan treatment, the RRD group underwent the same procedure. Intraocular pressure (IOP) measurement, fundus photography, B-mode ultrasound, optical coherence tomography (OCT), histology, and enzyme linked immunosorbent assay (ELISA) were performed.Retinas of all eyes in the RRD group were detached, whereas those of all eyes in the chitosan group remained attached. The concentrations of epidermal growth factor (EGF), fibroblast growth factor (FGF)-2, transforming growth factor β (TGF-β), vascular endothelial growth factor (VEGF), interleukin-6 (IL-6), and IL-8 in the vitreous fluid of the RRD group were significantly higher than those of the control group (p < 0.05). Furthermore, the concentrations of EGF, FGF-2, TGF-β, and VEGF in the vitreous fluid of the chitosan group were higher compared to those of the RRD group (p < 0.05), whereas the concentrations of IL-6 and IL-8 were lower (p < 0.05).Chitosan may be a reliable method for sealing retinal breaks. Moreover, chitosan can maintain high levels of growth factors and reduce inflammatory factors in the vitreous, which may reduce and delay the death of retinal cells and help restore visual function after retinal repositioning.© 2023 The Author(s). Published by Discovery Medicine.