# Anterior Ischemic Optic Neuropathy as a Paraneoplastic Manifestation of Colorectal Cancer

## TL;DR

A patient with sudden vision loss due to NAION was found to have an underlying colorectal cancer, highlighting the need to consider cancer in such cases.

## Contribution

This case report presents NAION as a paraneoplastic manifestation of colorectal cancer.

## Key findings

- A patient with NAION was found to have an underlying colorectal carcinoma.
- Systemic inflammation was identified as a potential link between NAION and the cancer.
- The case emphasizes the importance of investigating neoplastic causes in ischemic events.

## Abstract

Non-arteritic anterior ischemic optic neuropathy (NAION) is one of the most common causes of acute optic nerve-related vision loss. Its non-arteritic form is strongly associated with vascular risk factors. The role of systemic inflammation in its pathophysiology has increasingly been recognized, and it may coexist with prothrombotic or neoplastic states. We present the case of a patient with sudden vision loss and a diagnosis of NAION in the context of unexplained systemic inflammation, during the workup of which an underlying colorectal carcinoma was identified. This case highlights the importance of a comprehensive clinical approach to ischemic events, including the investigation of underlying inflammatory and neoplastic causes.