How to diagnose papilloedema

Papilloedema is optic disc swelling due to raised intracranial pressure (ICP). Typically, this occurs bilaterally, and visual function is usually relatively preserved unless the disease is moderately severe or chronic. The implications of a new finding of papilloedema are potentially serious; however, overdiagnosis of papilloedema can lead to iatrogenic harm from unnecessary investigation or treatment. It is important to consider the differential diagnosis for swollen optic disc appearances to ensure patients are investigated appropriately. We describe an approach to the clinical assessment of patients with suspected papilloedema, using history, examination and tools available in the eye clinic including perimetry and optical coherence tomography, as well as the pitfalls that may be encountered using these technologies. We also discuss a strategy for subsequent investigation of patients with probable papilloedema to identify causes of raised ICP, while highlighting potential pitfalls in this process.