Comparing the effects of different environments on the measurement of intraocular pressure and tear production in horses

TEARS/LIDS Burdur – The effects of two different environments – one familiar and one unfamiliar to the horse – on intraocular pressure (IOP) and tear production have not been studied. Harun Cinar et al. from the Department of Surgery, Faculty of Veterinary Medicine, Burdur Mehmet Akif Ersoy University, Burdur, Turkey, included 30 healthy male Arabian horses aged 6.88 ± 3.34 years in the cross-over study. Measurements of intraocular pressure and tear production were performed in both the home and the hospital stable. Statistical evaluation of the comparison was performed using paired t-test and Bland-Altman analysis.

A significantly higher IOP was observed in the hospital stable (34.2 ± 6.8 mm Hg) compared to the home stable (29.5 ± 7.2 mm Hg; p = 0.02). However, no statistically significant difference in tear production was found between the home stable (22.1 ± 2.8 mm/min) and the hospital stable (23.6 ± 3.4 mm/min) (p = 0.09). The standard error of the slope was 0.36 for the intraocular pressure (IOP) measured in the hospital stable, representing a difference of -4.7 mm Hg compared to the IOP measured in the home stable (p = 0.02). The bias was corrected accordingly. The standard error of the slope was 0.39 for the tear production measured in the hospital stable, which represents a difference of -1.5 mm/min compared to the tear production measured in the home stable (p = 0.09). Again, the bias was corrected for.

In the electronic preprint published by the EQUINE VETERINARY JOURNAL in January 2024, the authors state that the study was limited by the absence of horses with eye disease and by the lack of investigation of possible effects of transport. However, they can summarise that a significant increase in IOP was observed in the hospital stable compared to the home stable, while tear production did not show any significant differences between the two environments. Bland-Altman analysis showed a discrepancy between the IOP measurements in the stable, highlighting the possible influence of the environment on ocular parameters in horses. (bs)

Authors: Cinar H, Yanmaz LE, Buyukkaraca N, Kaya Z, Kosuncu M. Correspondence: Latif Emrah Yanmaz, Department of Surgery, Faculty of Veterinary Medicine, Burdur Mehmet Akif Ersoy University, Burdur, Turkey. Email: latifemrahyanmaz@gmail.com Study: Comparing the effects of intraocular pressure and tear production measurements in horses in two different environments: Horse stable and medical barn. Source: Equine Vet J. 2024 Jan 24. doi: 10.1111/evj.14067. Epub ahead of print. PMID: 38268120. Web: https://beva.onlinelibrary.wiley.com/doi/10.1111/evj.14067