Corneal hyperalgesia in patients with short tear film break-up time dry eye

To evaluate corneal tactile and pain sensations in patients with short tear film break-up time dry eye (sBUT DE).

This study enrolled 60 patients with sBUT DE and 46 healthy volunteers from Japan. We evaluated corneal tactile and pain sensations using a modified method with the Cochet-Bonnet corneal esthesiometer.

Patients with sBUT DE had higher corneal pain sensitivity (26.3 ± 23.1 mm) than healthy subjects (6.9 ± 16.4 mm), but similar corneal tactile sensation (52.0 ± 15.5 mm and 52.9 ± 14.9 mm, respectively). In patients with sBUT DE and corneal hyperalgesia (n = 22, 36.7%), defined as a pain sensitivity ≥40 mm (i.e., the cutoff value at the 95th percentile of corneal pain sensitivity in healthy subjects), a strong significant correlation was found between the subjective pain score and objective corneal pain sensation (R = 0.79). However, for the entire cohort, we found a weak positive correlation between the subjective pain score and objective corneal pain sensation.

Patients with sBUT DE were hypersensitive to corneal pain, which suggested that corneal hyperalgesia partly accounted for subjective symptoms in patients with sBUT DE.