Age-Related Changes in Corneal Sensitivity

Abstract

Purpose: The aim of this prospective cross-sectional cohort study was to clinically test whether corneal sensation decreases with age, based on subject feedback (psychophysical method), and whether it correlates with general pain perception. Methods: Subjects were recruited from 2 equally large age groups: group A (18–30 years) and group B (50–70 years; n = 45 per group). The inclusion criteria were healthy eyes, Ocular Surface Disease Index ≤13, and no contact lens wear. Corneal sensitivity threshold (CST) measurements were performed twice during each of the 2 visits, with the aid of the new Swiss liquid jet esthesiometer for corneal sensitivity (SLACS) and Cochet–Bonnet (CB) esthesiometer. A general pain sensitivity score was obtained from all participants. Results: Ninety subjects completed the study (n = 45 per age group, average age in group A: 24.2 ± 2.94 years, group B: 58.5 ± 5.71 years). Statistically higher CSTs for age group B were only observed for SLACS (mean difference: 1.58 dB, P < 0.001). No correlation was observed between the pain score and the CSTs obtained with either esthesiometry method (r = 0.11, P = 0.25 for liquid jet and r=−0.076, P = 0.61 CB). Conclusions: A statistically significant decrease in corneal sensitivity was observed for the older age group with SLACS in this study, with CB however only a trend in the same direction was noted. General pain perception was not found to correlate with ocular surface sensation.