Bilateral Exudative Chorioretinopathy in All-trans Retinoic Acid-Associated Differentiation Syndrome.

This report presents a rare case of bilateral exudative retinal detachment (ERD) as an early manifestation of differentiation syndrome (DS) in a woman in her early 30s undergoing induction therapy for acute promyelocytic leukemia (APL) with all-trans retinoic acid (ATRA) and arsenic trioxide. Nineteen days into therapy, she presented with bilateral blurring of vision. Ocular examination revealed bilateral multiple small closely spaced ERDs. Fundus autofluorescence and optical coherence tomography revealed focal retinal pigment epithelial disruptions. No systemic features of DS were recognised by the treating oncologist. ATRA was withheld, and systemic and topical corticosteroids were initiated, leading to complete resolution of subretinal fluid and full recovery of vision. ATRA was successfully reintroduced without recurrence of symptoms. This case highlights the potential for ocular findings to precede systemic signs of DS and underscores the importance of early ophthalmic evaluation and timely intervention to preserve vision and ensure uninterrupted leukemia treatment.