Abstract
Recent data suggest that corneal somatosensory dysfunction may be the underlying cause of
severe dry eye symptoms in the absence of ocular surface pathology seen in a subset of
patients diagnosed with “dry eye syndrome.” This subset of patients tends to demonstrate a
unique constellation of symptoms that are persistent, more severe, and generally respond
poorly to current dry eye therapies targeting inadequate or dysfunctional tears. A growing
body of literature suggests that symptoms in these patients may be better characterized as
neuropathic ocular pain rather than dry eye. In these patients, dry eye symptoms are often
associated with numerous comorbid pain conditions and evidence of central pain processing
abnormalities, where eye pain is just one of multiple overlapping peripheral
manifestations. In this review, we discuss the concept and potential mechanisms of chronic
overlapping pain conditions as well as evidence for considering neuropathic ocular pain as
one of these overlapping pain conditions.
