Corneal sensitivity repeatability with a new non-contact air jet corneal esthesiometer and comparison with Cochet-Bonnet esthesiometer.

Abstract

Purpose : The aim of the study was to assess the safety and repeatability of the measurements taken with a new non-contact esthesiometer -Brill Engines esthesiometer (BEE) and to compare the sensitivity obtained with the Cochet-Bonnet esthesiometer (CBE).

Methods : Young healthy male volunteers were included in the study. Corneal central sensitivity was measured with the new BEE and with the CBE. The procedure was performed three times on the same day and repeated in the same way for 3 days.
Measurement was performed according with the manufacturer instructions. BEE was mounted in the slit lamp and CBE measurement was used manually. A sub-umbral esthesiometry strategy was performed.
To assess whether the data followed a normal distribution, the Shapiro-Wilks test was used. Repeatability was determined by the intraclass correlation coefficient between each day. Likewise, the data obtained with the BEE were compared with those obtained with the CBE. They were also analyzed using the Bland-Altman test. A 95% confidence level was considered statistically significant.

Results : Nineteen consecutive healthy volunteers mean age 23.50 ± 3.62 years underwent and complete the participation in the study. Schirmer test was 7.47 ± 4.12 mm, with a range of 5 to 18 mm and OSDI test was 3.89 ± 3.59, with a range of 0 to 12.64.
No adverse effected, ocular surface or corneal damage were detected and both test were well tolerated by volunteers.
The mean values of corneal sensitivity measured with the BEE was 6.08 ± 0.30 mbar, with a minimum of 5 mbar and for the CBE was 0.61 ± 0.09 g/mm², with a minimum of 0,57 g/mm².
Intraclass correlation coefficient (ICC) of the BEE was 0.764 for a single measurement and 0.907 for the mean of all measurements. Correlation between both esthesiometers ICC was 0.388 and 0.559. Bland Altman plots showed the great majority of data were inside the boundaries (2 SD).

Conclusions : A new non-contact air jet corneal esthesiometer was tested in healthy volunteers with good tolerance, no adverse effects. The BEE showed good repeatability and correlation parameters. Brill Engines esthesiometer could be used as non-invasive alternative of the Cochet Bonnet esthesiometer.

This is a 2021 ARVO Annual Meeting abstract.