Study: Eyes with dry eye symptoms show increased conjunctival sensitivity

Pneumatic cool stimulation may heighten conjunctival and corneal sensitivity in patients with symptoms of ocular dryness who do not wear contact lenses, a study found. Particularly, these patients appear to have more significant conjunctival hyperesthesia.

Ping Situ, MB, MSC, and colleagues used a computer-controlled pneumatic esthesiometer with a stimulus temperature set at 20° C to compare conjunctival and corneal sensitivity among 97 right eyes of 97 subjects who were not contact lens wearers. Specifically, 43 of these participants had symptoms of ocular dryness and 54 were asymptomatic. For analysis, participants were divided into two groups based on age, with the younger group consisting of participants between 19 and 49 years of age and the older group consisting of participants between 50 and 80 years of age.

The investigators found that conjunctival and corneal thresholds were significantly less in eyes with dry eye symptoms than in asymptomatic eyes (P < .01).

Among eyes with dry eye symptoms, the conjunctival threshold was significantly lower than the corneal threshold (P < .01); however this difference was not evident in asymptomatic eyes, the authors noted.

In particular, women with asymptomatic eyes had a lower conjunctival threshold than men (P < .05).

There were no age-related differences for conjunctival and corneal thresholds, according to the study, published in the September issue of Optometry and Vision Science.