New method for assessing tear film break-up time and progression of corneal opacity in dogs

TEARS/LIDS / CORNEA Seoul – The aim of this study by Suk Jun Lee from the College of Business, Kwangwoon University, and colleagues from the College of Veterinary Medicine, Konkuk University, both in Seoul, Korea, was to determine the correlation between parameters that indicate the condition of the ocular surface and can predict corneal opacity.

Non-invasive tear break-up time (NIBUT) was measured in 50 dogs (96 eyes) using grid illumination. Thirty dogs (54 eyes) were included in the final analysis based on the established criteria. The results of NIBUT and tear film break-up time (TFBUT) were divided into three groups: Group 1 (< 5 s), Group 2 (5 to < 10 s) and Group 3 (≥ 10 s). The Schirmer Tear Test 1 (STT-1) results of the enrolled dogs were also divided into three groups: Group 1 (< 5 mm/min), Group 2 (5 to < 10 mm/min) and Group 3 (≥ 10 mm/min). The degree of corneal opacity was graded into four levels from 0 to 3. A Corneal Opacity Score (COS) of 0 indicates a completely clear cornea or only a trace of opacity. The other levels indicate corneal opacity that does not affect the visibility of fine iris details (COS 1), opacity that affects the visibility of iris and lens details (COS 2), or severe opacity that hinders the visibility of intraocular structures (COS 3).

The mean difference in the degree of corneal opacity during follow-up for each NIBUT group was 0.61 ± 0.92 (n = 28), 0.10 ± 0.32 (n = 10) and 0.19 ± 0.40 (n = 16), respectively. The NIBUT groups were significantly correlated with the COS (p = 0.073) at the 10% significance level. A post hoc test at the 10% significance level showed significant correlations between groups 1 and 2 (p = 0.041) and between groups 1 and 3 (p = 0.104). However, the TFBUT and STT-1 groups showed no significant correlation with COS. In the NIBUT test with grid illumination, eyes with NIBUT < 5 s were significantly more likely to have increased COS than eyes with NIBUT > 5 s. As the authors report in the April 2024 issue of FRONTIERS IN VETERINARY SCIENCE, NIBUT of STT-1, TFBUT and NIBUT was the only test to show significant associations with changes in corneal haze. (bs)

Authors: Lee SJ, Han MG, Yang SJ, Choi YS, Kim JY. Correspondence: Joon Young Kim, Department of Veterinary Ophthalmology, College of Veterinary Medicine, Konkuk University, Seoul, Republic of Korea. E-mail: canvet@konkuk.ac.kr Study: A novel method of evaluating the non-invasive tear film break-up time and progression of corneal opacification in dogs using imaging video. Source: Front Vet Sci. 2024 Apr 8;11:1298467. doi: 10.3389/fvets.2024.1298467. PMID: 38650850; PMCID: PMC11033512. Web: https://beva.onlinelibrary.wiley.com/doi/10.1111/evj.14067