FGFR1 and central serous retinopathy: More specifically, erdafitinib prevents the phosphorylation of FGFR1-4, and, thus, acts as a tyrosine kinase inhibitor [7,8]. Ultimately, this suppresses the downstream responses of overactive FGFRs and reduces the anti-apoptotic effects of FGFR activation (Figure 3) [9]. Central serous retinopathy (CSR) and retinal pigment epithelium detachment (RPED) are known side effects of FGFR inhibitors [7,10].