Assessment and safety of the new esthesiometer BRILL: Comparison with the Cochet-Bonnet Esthesiometer

Background: Corneal sensitivity can decrease by several ocular conditions, such as dry eye or refractive surgery, which favor ocular epithelial lesions and is measured using an esthesiometer. The study's primary objective was to demonstrate the efficacy and safety of the non-contact esthesiometer BRILL, which delivers air pulses to the corneal surface to assess corneal sensitivity. Methods: A single-center, prospective, controlled pilot study was carried out in adult patients with healthy eyes and or with pathology. Corneal sensitivity measurements were made in triplicate for both eyes at three consecutive visits. The esthesiometer BRILL was used in all visits, and on the last visit, the contact esthesiometer Cochet-Bonnet was also used. The results of both devices were compared by transforming them into force values. Results: 54 subjects with a mean age of 50.43 (SD 16.55, interval 18-87), 77.78% women, were included. Comparing the forces applied by both esthesiometers in the healthy eyes, in the eyes with pathology in all the groups, and in the dry eyes showed significant differences, p= 0.03603, p= 0.00614, and p= 0.0001, respectively. Conclusion: The BRILL esthesiometer proved to be an effective and safe tool for non-contact assessment of corneal sensitivity with operator-independent repeatability. The measurements had a good agreement and comparable range with the Cochet-Bonet aesthesiometer measurements in healthy and dry eyes but with no interchangeable values. This portable device can help ophthalmologists and optometrists to diagnose eye pathologies that cause decreased corneal sensitivity and to assess the efficacy of therapy and disease progression.