Evaluation of corneal mechanical sensitivity in Controls and Ocular Surface Disease patients using the Non-Contact Brill Engines Esthesiometer

Abstract

Purpose : To evaluate corneal mechanical sensitivity in healthy Controls and patients with Ocular Surface Disease (OSD) using the Non-Contact Brill Engines Esthesiometer (BEE).

Methods : This was a cross-sectional, descriptive study analyzing corneal sensation in two clinical groups using the BEE, a slit lamp mountable, non-contact esthesiometer that uses air-jet stimulation. Testing was performed per the manufacturer’s instructions, aligning the two LED indicators on the BEE screen with the inferior pupillary border for each shot. Corneal mechanical sensitivity was evaluated using incremental stimuli, obtaining three measurements per intensity level. The mean pressure detected by the esthesiometer and the percentage of patients perceiving the stimulus at each level were calculated. A two-way ANOVA test was performed to compare the proportion of patients detecting the stimulus at different intensity levels.

Results : Ninety-five eyes from 49 patients (51% female) were evaluated for this study, with 15 healthy patients as Controls and 34 patients in the OSD group. All patients underwent a comprehensive slit lamp exam, fluorescein ocular surface evaluation and took the DEQ-5 questionnaire (Control mean score 1.6 +/- 2.13; OSD 10.35 +/- 4.07). Mean age was 52.85 +/- 18.01 years. There were no adverse effects, and all patients well tolerated the procedure. The mean pressure readings for corneal sensitivity obtained with the BEE were 5.21 +/- 2.41 mBar, with minimal and maximal values of 1 and 9 mBar.
Statistically significant differences in the perception of stimulus between the Control and OSD groups were found in the esthesiometer's 2nd, 3rd, and 4th intensity levels. The percentage of patients in the Control group compared to the OSD group that detected the stimulus on levels 2, 3, and 4 were 90% vs. 77.95% (p=0.0395), 100% vs. 81.03% (p=0.0002), and 100% vs. 86.15% (p=0.0116), respectively. No significant differences between the groups in the 1st and 5th levels were found.

Conclusions : The Non-Contact Brill Engines Esthesiometer was tested in healthy Controls and patients with OSD, proving reliable and safe. Importantly, this new instrument has the capability to detect differences in corneal sensation between healthy and diseased populations through a convenient, non-invasive, and well-tolerated approach.

This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.