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UC Davis Having Success with Nasolacrimal Endoscopy

October 29, 2014

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The small nasolacrimal duct can become blocked causing infection and irritation.

A new, multidisciplinary minimally invasive approach to nasolacrimal obstructions is showing great promise at the UC Davis Veterinary Medical Teaching Hospital. The lacrimal system is responsible for the generation and drainage of tears. The drainage portion of the system consists of several important structures collectively known as the nasolacrimal apparatus (NLA). This frequently becomes blocked and sometimes infected leading to discomfort, tear staining and discharge from the eye, resulting in skin inflammation. However, the NLA is made up of such small vessels that access to the obstruction can be extremely difficult.

Improvements in instrumentation and increased veterinary access to specialized equipment have improved the outcomes achieved in catheterization of other challenging locations (e.g., cannulation of the ureter, or tube draining urine from the kidney to the bladder), and a group of VMTH clinicians have begun adapting some of this equipment and these techniques for investigation and treatment of NLA obstructions. 

Specialists in ophthalmology, internal medicine, endoscopy, and interventional radiology have come together and are utilizing fluoroscopy to successfully treat NLA obstruction in dogs. To date, this team has successfully cannulated the nasolacrimal duct of five canine cases and one equine case of benign NLA obstruction. The initial clinical response in the dogs has been extremely encouraging with all five cases demonstrating what the owners define as a complete resolution of signs.

Importantly, these cases are considered particularly challenging since they were referred to the VMTH by local ophthalmologists who had been unable to treat them using conventional methods. Because of this initial success, a clinical trial is now underway at the VMTH to evaluate the procedure so that this can become the standard-of-care for this otherwise frustrating disease complex.

If you are interested in referring a patient to this study, please contact the VMTH Ophthalmology Service at (530) 752-EYES (3937).

About the Veterinary Medical Teaching Hospital
The William R. Pritchard Veterinary Medical Teaching Hospital at the University of California, Davis—a unit of the School of Veterinary Medicine—provides state-of-the-art clinical care while serving as the primary clinical teaching experience for DVM students and post graduate veterinarian residents. The VMTH treats more than 47,000 animals a year, ranging from cats and dogs to horses, cows and exotic species. To learn more about the VMTH, please go to Timely news updates can be received on its Facebook ( and Twitter ( pages.

Rob Warren
VMTH Communications & Marketing Officer