Phenotypic characterization of patients developing chronic dry eye and pain after refractive surgery: A cross-sectional study

To describe the clinical characteristics of patients suffering from chronic dry eye (DE) and pain after refractive surgery (RS). Cross-sectional, observational, single-visit study. DE-, pain- and psychological-related symptoms were evaluated with specific questionnaires. DE-related tests evaluated tear osmolarity, conjunctival hyperemia, Meibomian gland dysfunction, tear stability and production, and ocular surface staining. Corneal mechanical sensitivity (Cochet-Bonnet) was measured pre/post topical anesthesia, and symptomatic variation post-anesthesia (anesthetic challenge test) was recorded. When pain was present, it was further categorized as neuropathic or nociceptive based on published criteria. We recruited 104 patients (39.5 ± 9.5 years). Most, 85.6%, had corneal RS as opposed to intraocular RS. Migraines, anxiety, depression (p < 0.0001), and central sensitization syndromes (p = 0.0214) were more frequent post-RS than pre-RS. Persistent DE-symptoms, severe in 86.5% patients, developed in a range of 0–204 months post-RS. Dryness and pain were the two most frequent symptoms. The only DE-related tests showing abnormal values were tear osmolarity (315.2 ± 17.1 mOsm/L; normal ≤308) and tear break-up time (4.1 ± 2.5 s; normal >7). Corneal sensitivity was 55.4 ± 7.0 mm, and decreased (p < 0.0001) after topical anesthesia, 6.0 ± 10.4 mm. However, it remained pathologically elevated, ≥10 mm in 61 (58.7%) patients. The normal symptomatic post-anesthesia improvement was absent in 58 (55.7%) patients. Ocular pain was present in 82 (78.8%) patients, and it was categorized as neuropathic in 66 (80.5%) of them, 63.5% of the entire cohort. Chronic ocular pain and its neuropathic subtype were diagnosed in 78.8% and 63.5% respectively of patients seeking consultation for persistent symptomatic DE post-RS.