Effect of auriculopalpebral nerve block on Schirmer tear test I values in normal horses.

This study explored the impact of auriculopalpebral nerve block on Schirmer tear test I (STTI) values in healthy horses and found that the nerve block didn’t significantly influence the test results.

Introduction

• The research was focused on examining the effect of an auriculopalpebral nerve block on the outcomes of the Schirmer tear test I (STT I) – a common veterinary diagnostic test used to measure tear production – in healthy horses.
• Comparisons were made between STT I values collected from the eyes of horses with and without the nerve block procedure.

Methods

• A total of 20 clinically normal horses (38 eyes), with a median age of 12 years, were included in the study.
• The eyes were tested, with their order of testing randomized for unbiased results.
• The tear measurements of the same eyes were again collected between 24 and 48 hours later, after the administration of an auriculopalpebral nerve block. This block procedure was performed at least 5 minutes prior to STT I.
• Data analysis involved a repeated-measures model that considered differences between STT I values for eyes with and without nerve blocks, and accounted for within-horse correlation between eyes.
• The statistical analysis model used also included fixed factors (treatment and eye) and a random intercept for each horse.

Results

• On average, the post-nerve-block STT I values turned out to be 0.55 mm/min higher compared to the results gathered without the nerve block applied.
• However, the revealed difference was not statistically significant (P = 0.5268), indicating that the nerve block didn’t have a substantial influence on the STT I values.

Conclusions

• The key finding of the research was that an auriculopalpebral nerve block does not noticeably affect the STT I measurements in normal horses.
• This outcome could help streamline diagnostic procedures in veterinary practice.