An investigation into the development of qualitative tear film disorders in dogs following cryoepilation for distichiasis.

Objective: The aim of this prospective study was to compare tear film quality between dogs who have previously undergone cryoepilation for distichiasis to a reference population.
Animals Studied: Nine dogs (17 eyes) were recruited after surgery and were compared to a reference population of 21 dogs (42 eyes).
Procedures: Canine patients who had previously undergone cryoepilation for distichiasis for a minimum of 1 month prior to examination were recruited. A complete ophthalmic examination was performed by an ABVO resident (BDR), with additional tear tests, including tear film interferometry, infra-red meibography, and a tear film break-up time (TFBUT) performed. The tear test results were compared to a reference population obtained from client-owned dogs with no history of ophthalmic complaints, a normal ophthalmic examination performed by an ABVO resident (BDR) and a Schirmer Tear Test-1 > 15 mm/min. Statistical analysis was performed of the results obtained.
Results: The treated group was significantly more affected with meibomian gland dropout (MG-dropout) in 11/17 (64.7%) cases, compared to the reference population of 2/21 (9.5%) (p < .01). The treated group had an odds ratio of 23.8 to develop MG-dropout compared to the reference population (p < .01). Tear film breakup time (TFBUT) was significantly shorter in the treatment group (5.8 ± 2.6 s) compared to the reference population (10.1 ± 1.1 s) (p < .001). In the treatment group, 12/17 (70.5%) of treated eyes had a TFBUT < 5 s compared to 2/21 (9.5%) of the reference population.
Conclusion: Cryoepilation for distichaiasis appears to be a risk factor for developing MG-dropout and qualitative tear film disorders post-operatively in canines.
(© 2022 American College of Veterinary Ophthalmologists.)