Peer-reviewed veterinary case report
Measuring dog tear production with eyes open or closed
By Pe'er, Oren et al.·Published in Veterinary ophthalmology·2025·Koret School of Veterinary Medicine·View original on PubMed →
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Original publication title: Schirmer tear test-1 with open or closed eyelids: An evaluation in brachycephalic and nonbrachycephalic dogs.
- Species:
- dog
Plain-English summary
A study looked at how tear production in dogs varies when their eyelids are open or closed during a tear test. They tested 30 healthy dogs, including 15 Shih Tzus and 15 Labrador Retrievers, and found that tear production was significantly higher when the dogs' eyelids were closed. This difference was notable, with Labradors producing up to 13 mm/min more tears when their eyes were closed compared to open. The results suggest that for accurate tear production measurements, it's important to keep the eyelids closed during the test.
People also search for: dog eye tear test · why is my dog’s eye watering · Shih Tzu tear production test · Labrador Retriever eye problems
Abstract
PURPOSE: Assess aqueous tear production when measured with the dogs' eyelids open or closed. METHODS: Thirty healthy dogs (15 Shih Tzus, 15 Labrador retrievers) were recruited. With the order of testing randomized for each dog, two sessions (separated by 30 min) of STT-1 testing were performed with the dogs' eyelids closed or open. Schirmer strip wetness (every 10 s for 60 s) and number of time(s) the strip dislodged during testing were recorded in each eye. Preferred STT-1 method was surveyed via a global Listserv of the veterinary ophthalmology community. RESULTS: STT-1 values were significantly higher in closed versus open eyes in Shih Tzus (18.6 ± 2.7 mm/min vs. 16.3 ± 2.5 mm/min; p = .002) and Labrador retrievers (21.6 ± 2.9 mm/min vs. 17.8 ± 3.2 mm/min, p < .001), findings that were also significant at times <60 s for either breed (p ≤ .004). Schirmer strips dislodged from six dogs with open eyelids and no dogs with closed eyelids. Maximal STT-1 difference with closed versus open eyelids was 13 mm/min in Labrador retrievers and 7 mm/min in Shih Tzus. Survey results from 275 veterinarians showed STT-1 performed with "closed eyelids" (38.5%), "open eyelids" (26.9%), or "never paid attention, sometimes closed, sometimes open" (34.6%). CONCLUSIONS: Eyelids status (closed or open) during STT-1 testing had a significant impact on aqueous tear secretion in brachycephalic and nonbrachycephalic dogs, highlighting the importance of consistency when repeating STT-1 in a canine patient. STT-1 differences are likely due to sustained reflex tearing throughout the test duration when the dogs' eyelids are closed.
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Search related cases →Original publication on PubMed: https://pubmed.ncbi.nlm.nih.gov/38654458/