Purpose: The current study investigated the normative data values and repeatability of non-invasive tear film tests using Oculus Keratograph 5M in rabbit eyes.
Methods: Triplicate analysis of tear film parameters [tear meniscus height (TMH), non-invasive tear break up time (NIBUT), bulbar congestion, meibography] of 38 healthy adults New Zealand white rabbits (mean age, 13 ± 4.7 months) was performed using Oculus keratograph 5M (K5M). Bland-Altman analysis was used for testing repeatability.
Results: Thirty-eight rabbits (N = 76 eyes) weighing 2.5 ± 0.4 kg were studied. The mean NIBUT values of the right and left eye were 14.3 ± 5.8 and 12.3 ± 5.8 s, respectively. The mean central TMH values were 0.43 ± 0.23 and 0.33 ± 0.14 mm in the right and left eye, respectively. Meibography showed closely placed, wide meibomian glands running vertically with no distorted or gland loss areas. There were no differences between the eyes for the above parameters. Bland-Altman plot showed good repeatability for both NIBUT and TMH values.
Conclusion: The non-invasive tear film parameters show good repeatability using keratograph 5M and can be used as an objective parameter for rabbit ocular surface experiments.
Keywords: Rabbit; dry eye disease; keratograph; non-invasive tear break-up time; tear meniscus height.