Pemetrexed and carboplatin-induced exacerbation of ocular inflammation in choroidal metastasis secondary to non-small cell lung cancer

A 33-year-old woman presented with unilateral vision loss and significant weight loss. Examination showed counting fingers vision, relative afferent pupillary defect, a choroidal mass, and exudative retinal detachment (RD). Imaging revealed a primary lung tumor with multiorgan metastasis, including intraocular involvement. Lung biopsy confirmed adenocarcinoma. She began chemotherapy with pemetrexed and carboplatin but experienced worsening ocular inflammation after one cycle, with severe chemosis, lid edema, restricted eye movement, leukocoria, and increased tumor size and RD. IV dexamethasone followed by oral prednisolone controlled inflammation, and chemotherapy was continued. After five cycles, she developed skin reactions, prompting a switch to oral Afatinib. Eight months later, systemic and ocular improvements were noted, though vision remained poor due to retinal and optic nerve damage. This is the first reported case of pemetrexed and carboplatin exacerbating ocular inflammation in choroidal metastasis. Careful monitoring of chemotherapy-related ocular side effects and research into their underlying mechanisms is warranted.