OBJECTIVE: Compare the accuracy of the tonometers, Tonovet, Tonovet Plus, Tono-Pen Avia Vet, and Kowa HA-2 in dogs. METHODS: A postmortem study (n = 10) comparing the values of manometry versus tonometry and calculating the correlation coefficient (r2). An in vivo study (n = 10) was performed comparing the real IOP (manometry) with the tonometers and an ambulatory study in anesthetized healthy dogs (n = 20). An ambulatory study, eyes with signs of glaucoma (n = 10) and uveitis (n = 10) were analyzed. RESULTS: The post-mortem study of (r2) in decreasing order: Kowa HA-2 (0.989), Tonovet Plus (0.984), Tonovet (0.981), and Tono-Pen (0.847). The IOP values in mmHg in the in vivo study: aneroid manometer (16.8 ± 1.7), Tonovet (18.1 ± 2.9), Tonovet Plus (20.6 ± 2.3), Tone-Pen (17.1 ± 2.5), and Kowa (16.1 ± 1.7). In the ambulatory study: healthy Tonovet (16.2 ± 2.8), Tonovet Plus (19.9 ± 3.4), Tono-Pen (15.3 ± 3.0), and Kowa (14.6 ± 1.9); glaucoma Tonovet (30.9 ± 5.9), Tonovet Plus (35.0 ± 8.3), Tono-Pen (28.4 ± 5.8), and Kowa (23.8 ± 4.4); and uveitis Tonovet (14.2 ± 5.6), Tonovet Plus (17.9 ± 5.5), Tono-Pen (13.3 ± 6.3) and Kowa (10.7 ± 4.0). CONCLUSIONS: There was a strong correlation between the IOP values with the manometry and all tonometers. The highest values were mensuremented with Tonovet Plus and the lowest with Kowa. All tonometers were accurate in the IOP measurement in dogs, including the most recent, Tonovet Plus, which showed an excellent correlation coefficient.
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