Chronic Ocular Surface Pain: A Missing Member of the Chronic Overlapping Pain Conditions?

Chronic overlapping pain conditions (COPCs) comprise a cluster of ten chronic pain disorders that frequently co-occur and are conceptualized as sharing centrally mediated or nociplastic mechanisms. Chronic ocular surface pain (COSP), defined as ocular surface pain lasting more than three months, has traditionally been classified under "dry eye disease." However, emerging evidence suggests that in a subset of individuals, COSP shares important clinical and mechanistic features with COPCs, supporting the need for an updated synthesis as increasing data implicate central contributions to pain. This narrative review examines COSP within the broader COPC framework across epidemiology, risk factors, pathophysiology, diagnosis, and treatment, and proposes that in select cases, COSP may warrant conceptual consideration as an additional COPC. Across the literature, COSP shares several similarities with COPCs, including high prevalence, female predominance, and increasing frequency with age. Chronic ocular surface pain also commonly clusters with COPCs and, when nociplastic features are present, is associated with psychosocial comorbidity. Mechanistically, COSP in some individuals demonstrates characteristics of nociplastic pain, including symptom-sign discordance, persistent pain despite topical anesthesia, multisite hyperalgesia, and altered functional connectivity within central pain and sensory processing networks. Collectively, current evidence supports substantial overlap between COSP and COPCs within a nociplastic framework, suggesting that COSP may be best understood, in part, within this broader construct. Recognizing COSP in the context of COPCs has important implications for mechanism-based approaches to diagnosis, treatment, and future research aimed at improving outcomes.