Clinical characteristics of dry eye with ocular neuropathic pain features: comparison according to the types of sensitization based on the Ocular Pain Assessment Survey

Background: To compare the clinical characteristics of dry eye patients with ocular neuropathic pain features according to the types of sensitization based on the Ocular Pain Assessment Survey (OPAS). Methods: Cross-sectional study of 33 patients with dry eye and ocular neuropathic pain features. All patients had a comprehensive ophthalmic assessment including detailed history, the intensity and duration of ocular pain, the tear film, ocular surface, and Meibomian gland examination, and OPAS. Patients with < 50% improvement in pain intensity after proparacaine challenge test were assigned to the central-dominant sensitization group (central group) and those with ≥50% improvement were assigned to the peripheral-dominant sensitization group (peripheral group). All variables were compared between the two groups. Results: No significant differences were observed in age, sex, underlying diseases, history of ocular surgery, duration of ocular pain, tear film, ocular surface and Meibomian gland parameters (all p > 0.05). Ocular pain and non-ocular pain severity and the percentage of time spent thinking about non-ocular pain were significantly higher in the central group than in the peripheral group (all p < 0.05). Central group complained more commonly of a burning sensation than did the peripheral group (p = 0.01). Conclusions: Patients with central-dominant sensitization may experience more intense ocular and non-ocular pain than the others and burning sensation may be a key symptom in those patients.