RESUMEN
Our aim is to describe clinical and optical coherence tomographic features of acute paraneoplastic focal outer retinitis associated with optic neuropathy in a patient diagnosed with small cell lung carcinoma. Bilateral focal outer retinitis, bilateral optic disc oedema and vitritis were identified in a patient with progressive bilateral visual loss and ataxia. Spectral domain optical coherence tomography (SD-OCT) revealed various extents of granular hyperreflectivity and atrophy of the macular outer retinal layers. Serum and cerebrospinal fluid positivity for anti-CRMP5, anti-HU and anti-amphiphysin antibodies intensified the search for an underlying malignancy, and a small cell lung carcinoma (SCLC) was finally diagnosed. Local and oral steroids along with systemic chemotherapy and radiotherapy achieved cancer remission and partial recovery from the ophthalmic manifestations. Focal outer retinitis associated with optic disc oedema and antibody positivity facilitated the diagnosis of SCLC in a localized stage. SD-OCT allowed the characterization of this entity, expanding the spectrum of paraneoplastic ophthalmological syndromes.