Patients with more severe symptoms of neuropathic ocular pain report more frequent and severe chronic overlapping pain conditions and psychiatric disease

Objective To study chronic pain and mental health profiles in patients with dry eye (DE) symptoms, comparing those with high and low levels of neuropathic ocular pain (NOP) complaints. Design Cross-sectional study of 181 patients with DE symptoms (dry eye questionnaire score >= 6) seen in the Miami Veterans Affairs eye clinic. An evaluation was performed consisting of questionnaires regarding DE symptoms, NOP complaints (burning, sensitivity to wind, light and cold/hot temperatures) and pain elsewhere in the body (non-ocular). This was followed by a comprehensive ocular surface examination. The patients' comorbidities, medications, mental health (depression and post-traumatic stress disorder) and quality-of-life indices were also obtained. Patients were classified using cluster analysis into either the 'high NOP' or 'low NOP' group. Subsequent analyses were performed to examine differences in ocular and non-ocular parameters between these two groups. Results Despite similar ocular surface findings, patients in the high NOP group had very different systemic (non-ocular) profiles with higher overall pain intensity ratings, higher frequency of comorbid chronic centralised pain conditions, lower quality-of-life indices and more abnormal mental health scores than those in the low NOP group. Conclusions Consistent with a chronic overlapping pain condition, patients with DE disease with more severe NOP symptoms report more frequent and severe non-ocular functional comorbid pain disorders.