Rhegmatogenous retinal detachment (RRD) is a serious ocular condition marked by the separation of the neuroretina from the retinal pigment epithelium (RPE). The pathogenesis of RRD involves intricate molecular and cellular mechanisms, including inflammation, cell migration, and the activation of proliferative signaling pathways. One of the most challenging complications of RRD is proliferative vitreoretinopathy (PVR), which refers to the proliferation and contraction of fibrocellular membranes on the retinal surface and in the vitreous cavity. PVR is a major cause of surgical failure in RRD, as it can lead to recurrent retinal detachment and severe vision loss. However, the pathogenesis of PVR is not yet fully understood, and the treatment options are quite limited. Recent advances in analytical techniques have offered valuable insights into the molecular alterations present in the subretinal fluid (SRF) of patients with RRD. This review seeks to consolidate the current knowledge regarding the SRF profile in RRD and PVR, emphasizing potential biomarkers and therapeutic targets.