Complexity of recognising, diagnosing and managing corneal neuropathic pain

The cornea is the most densely innervated tissue in the body, yet the pain that arises when its nerves misfire remains one of ophthalmology’s least understood clinical presentations. Neuropathic corneal pain (NCP) is known by many interchangeable names in the literature, including corneal neuralgia, keratoneuralgia, ocular neuropathic pain and ‘phantom cornea’, 1 a terminological scatter that hints at a deeper problem. NCP describes severe, often disabling ocular pain that is disproportionate to or occurs in the absence of clinical signs: so-called ‘pain without stain’.2 3 Patients are frequently treated for presumed dry eye disease (DED) for months or years before the diagnosis is even considered, by which point distress, lost working days and occasionally suicidal ideation may already have accrued.4