Effects of Tear Film Instability on Sensory Responses to Corneal Cold, Mechanical, and Chemical Stimuli
•The effects of tear film instability (TFI) induced by sustained tear exposure (STARE) on sensory responses to corneal cold, mechanical, and chemical stimuli were evaluated in current study.
•In 15 normal subjects pneumatic cold, mechanical, and chemical stimuli were delivered using a Belmonte esthesiometer on three separate visits. Symptoms of ocular discomfort were evaluated using the Current Symptom Questionnaire (CSQ).
•In Repeated TFI induced by STARE affects neurosensory function of the ocular surface. The decrease in reports of cooling and increase in irritation after repeated TFI suggest a complex interaction of neural mechanisms (particularly non-nociceptive cold and nociceptive mechanical) giving rise to ocular surface sensation in humans.
•In this study, the tear film instability was induced by sustained tear exposure, and its effects were measured by scoring responses by the participants.
•The authors observed that the reports of cooling decreased along with an increase in irritation after repeated tear film instability.
•These findings demonstrate the effects of tear film instability on neurosensory function of the ocular surface and suggest a complex relationship between cold and mechanical neural mechanisms of sensation.
Reference: Situ P, Begley CG, Simpson TL. Effects of Tear Film Instability on Sensory Responses to Corneal Cold, Mechanical, and Chemical Stimuli. Invest Ophthalmol Vis Sci. 2019 Jul 1;60(8):2935-2941