Cancer-associated retinopathy and optic neuropathy in a patient with lung adenocarcinoma

Paraneoplastic vision loss includes a heterogenous group of ocular disorders that occur in the setting of systemic malignancy. The presenting symptoms are variable, but typically include vision loss that is painless, subacute in onset, and ultimately bilateral. The underlying mechanism is thought to involve molecular mimicry due to structural homology between ocular and cancer antigens. Presentations of paraneoplastic vision loss include cancer-associated retinopathy, paraneoplastic optic neuropathy, paraneoplastic vitelliform maculopathy, bilateral diffuse uveal melanocytic proliferation, melanoma-associated retinopathy, and opsoclonus-myoclonus syndrome. Very few cases have reported simultaneous retinopathy and optic neuropathy. Here we present the case of a 36-year-old female who developed complete vision loss in the right eye, with both retina and optic nerve changes. Extensive investigation revealed a non-mucinous lung adenocarcinoma. We suggest use of the term CARON (Cancer-Associated Retinopathy and Optic Neuropathy) for cases such as these.