Measuring corneal pain in the clinic

Abstract

DED is a heterogenous disease with a variety of symptoms and signs. One reality of the disease is that its symptoms (e.g., ocular surface pain described as “dryness”, “irritation”, “aching”, and/or “tenderness”) often do not align with its signs (e.g., decreased tear production, tear instability). New data suggest that corneal nerve abnormalities underlie the noted discordance between symptoms and signs. DED symptoms out of proportion to signs, as is often seen co‐morbid with pain conditions such as migraine and fibromyalgia, may indicate that neuropathic mechanisms contribute to symptoms. DED signs out of proportion to symptoms, as is often seen co‐morbid with diabetes mellitus, may indicate that neurotrophic mechanisms are involved. Given this reality, testing for corneal nerve function is an important, but often overlooked, component of the ocular surface examination. This presentation will review strategies to test corneal nerve function in the clinical arena, and discuss treatments that can be used when corneal nerve abnormalities are detected.