Application of OSA-VET^® and qualiquantitative tear tests in brachycephalic dogs with and without keratoconjunctivitis sicca

The aim was to compare the outcomes acquired from the OSA-Vet^® device with conventional quantitative and qualitative tear tests and between groups within each test, in brachycephalic dogs both healthy and those diagnosed with keratoconjunctivitis sicca. The dogs were divided into four groups: healthy dogs (HD), with mild KCS (MIKCS); moderate KCS (MOKCS); severe KCS (SKCS). All patients underwent ocular surface diagnostic examination in the following order, with a 10-minute interval between tests: non-invasive tear film breakup time (TBUTNI - OSA-Vet^®), tear meniscus height (TMH-OSA-Vet^®), meniscometry (I-Tear^® test), Schirmer Tear Test-1 (STT-1), and tear film breakup time (TBUT). Kruskal-Wallis H tests were performed to establish the difference between the groups and Spearman´s correlation coefficient test to assess the correlation between tests. And an analysis of variance (ANOVA) followed by Tukey-Kramer post-hoc test was performed for TMH. Results with (p <.05) were considered statistically significant. The correlation of conventional tests in relation to those obtained by OSA-Vet^® proved to be low, except between TBUTNI (OSA-Vet^®) and TBUT in MOKCS, with a strong correlation (r =.925). In the comparison between TBUTNI (OSA-Vet^®) and TBUT in MIKCS the correlation was moderate (r =.547) as well as STT-1 and I-Tear^® test in MOKCS (r =.416). In the comparison between groups, the main result observed was a significant difference between all the KCS groups and HD, in the TBUT and TBUTNI (OSA-Vet^®) test. The OSA-Vet^® and conventional tests are useful for evaluating the ocular surface of brachycephalic dogs. However, the OSA-Vet^® does not correlate well with conventional standardized tests.