Toxic maculopathy associated with systemic carboplatin therapy: a case report

To describe a potential first case of carboplatin-induced macular toxicity occurring during systemic treatment for metastatic non–small cell lung cancer (NSCLC). Retrospective case report with a literature review. A 48-year-old man developed bilateral vision loss three days after receiving first two cycles of chemoimmunotherapy consisting of carboplatin (400mg/m 2 ), pemetrexed (500mg/m 2 ), and pembrolizumab (200 mg) administered intravenously every four weeks. Clinical evaluation revealed rapidly progressive bilateral visual decline with a central scotoma. Multimodal imaging demonstrated foveal hyper-autofluorescence and disruption of the foveal ellipsoid zone in both eyes. Electrophysiological testing showed foveal peak impairment on multifocal ERG, consistent with a toxic mechanism. Fluorescein and indocyanine green angiography performed at a distance does not show any ischemic or exudative phenomena. Ocular and systemic findings were not suggestive of a paraneoplastic process. Following discontinuation of carboplatin, anatomical and functional abnormalities stabilized. Carboplatin-induced toxic maculopathy is rare and may result in visual acuity loss. Multimodal imaging indicates involvement of foveal photoreceptor. The reversibility of structural and functional changes after treatment cessation remains uncertain. Given the uncertainty regarding both causality and the underlying mechanism, this case highlights the importance for oncologists and ophthalmologists to promptly evaluate any visual complaints arising during carboplatin therapy.