Abstract
We report two cases of fibroblast growth factor receptor (FGFR) inhibitor-associated retinop-athy, including the first case of Debio 1347 associ-ated retinopathy manifesting with bilateral serous retinal detachments along the superotemporal ar-cades and a case of erdafitinib associated retinopa-thy manifesting with classic foveal serous retinal detachments. Both cases demonstrate a clear dose -dependent and reversible class effect likely sec-ondary to downstream effects of FGFR inhibition on the MEK pathway, resulting in retinal pigment epithelial cell dysfunction, and may also involve additional mechanisms of cellular injury through inhibition of the PI3K/AKT/mTOR pathway. FGFR inhibitor-associated retinopathy appears to mani-fest differently among patients.