Abstract
Purpose :
Corneal nociceptors respond to mechanical, chemical and polymodal stimuli. The Cochet-Bonnet (CB) esthesiometer quantifies only mechanical sensitivity and determines hypo- or normal sensitivity. However, hypersensitivity has not been measured to date. Thus, we aim to assess the correlation of the novel non-contact esthesiometer (NCE, Brill Engines) to the CB in patients diagnosed with ocular surface diseases (OSD) with and without ocular pain
Methods :
A retrospective, cross-sectional study of patients with OSD, with or without ocular pain in which NCE followed by CB was used in clinic was conducted. The NCE protocol started at the lowest air pressure and increased gradually (levels 1 to 5). Measurements with both devices were concluded upon confirmation of the sensation at the lowest stimuli. Experiencing sensation with the NCE lowest level (1) suggested hypersensitivity. Spearman’s rho test compared CB and NCE measurements
Results :
The study included 80 eyes from a total of 80 patients. There was no difference in age (p=0.70) nor gender (p=0.45) between groups. The median (range) values for the entire cohort using NCE was 4.0 (0-5), while for CB, it was 6.0 (0-6). Subgroup analysis within the pain group revealed NCE's median score as 4.0 (0-5), contrasting with CB's median of 6.0(0-6). Conversely, in the group without pain, NCE showed a median score of 3.0(1-5), while CB displayed a median of 6.0(1-6). Overall, we found a significant, but weak inverse correlation between NCE and CB (ρ=-0.253, p=0.023). NCE level 1 (n=20) suggested that these patients were hypersensitive, which CB was not able to measure differently (6.0 cm). Patients not responding the highest NCE level 5 showed positive sensation with CB (0.5 cm), suggesting that NCE might not measure the most severe neurotrophic state. Stratifying the patients by the presence of pain, there was a significant moderate inverse correlation between NCE and CB in pain group (n=52, ρ=-0.307, p=0.027). However, there was no significant correlation in patients without pain (n=28, ρ=-0.166, p=0.399)
Conclusions :
NCE and the CB yield weak to moderate correlations, indicating that they may not be measuring similar corneal sensitivity in patients with OSD with and without pain. NCE has the advantage of potentially measuring hypersensitivity that cannot be measured by CB, why CB is able to measure sensation at the most severe neurotrophic states
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.