Non-contact esthesiometer: Large cohort study on agreement with contact method and correlations with corneal nerves and ocular surface

Purpose: To evaluate the repeatability of non-contact Brill esthesiometer (NBE), its agreement with Cochet-Bonnet esthesiometer (CBE), and the relationship between corneal sensitivity, corneal nerve metrics and ocular surface parameters.Design: Cross-sectional study. Subjects:This study included 880 eyes, comprising healthy controls (80 eyes), dry eye disease (DED, 170 eyes), neuropathic corneal pain (NCP, 140 eyes), post-refractive surgery (P-RS, 176 eyes), and diabetes mellitus (DM, 314 eyes).Methods: NBE and CBE measurements were obtained at central and four peripheral corneal quadrants.Both measurements were converted to millinewtons (mN) for analysis.In-vivo confocal microscopy for seven corneal nerve parameters and four ocular surface parameters were assessed.Main Outcome Measures: Agreement between NBE and CBE measurements. Correlations between NBE measurements