Dry-eyed at last: Nasolacrimal stenting procedure corrects a cat's tear duct obstruction

A tear-free success. Kinako was the first cat treated for a blocked nasolacrimal duct using UC Davis' pioneering procedure. (Photos courtesy of UC Davis)

After a computed tomography (CT) scan revealed a tear duct obstruction in Kinako, an 8-year-old female domestic shorthaired cat, she underwent a new procedure pioneered at the University of California, Davis, Ophthalmology Service to permanently reopen the duct.

David Maggs, BVSc, DACVO, and Ann Strom, DVM, MS, suggested this new, minimally invasive approach that involves placing a stent to treat the cat. This therapeutic approach to nasolacrimal obstructions had already shown great promise in one horse and a number of dogs, but, until Kinako, had not yet been performed in a cat.

The stent technique

Kinako had been referred to UC Davis because of a continual buildup of tears in her left eye, sometimes resulting in infections. While the situation was not life-threatening, Kinako's owner did not want her to suffer needlessly for the rest of her life.

As they had done before for the equine and canine patients, a multidisciplinary team of clinicians from UC Davis' Ophthalmology, Internal Medicine, Soft Tissue Surgery, Anesthesia and Diagnostic Imaging Services came together to successfully unobstruct and temporarily stent Kinako's left nasolacrimal passage. After the surgery, the stent was left in place for two months to allow adequate time for the duct to heal in an open position.

A work in progress. Kinako, recovering after the placement of a temporary stent to correct an obstructed nasolacrimal duct. The stent was left in place for two months to allow adequate time for the duct to heal in an open position.

The UC Davis team used endoscopy, CT and fluoroscopy to identify and bypass or remove the nasolacrimal obstruction. Whether a scarred duct or a foreign body causes an obstruction, temporary stents can usually be placed to reopen the duct from eye to nose.

Cheers for no tears

Although Kinako initially had some persistent ocular discharge caused by an infection in the tissue around the eye, this cleared with antibiotics, and Kinako's left eye no longer shows signs of buildup or excessive tearing. Her nasolacrimal duct remains clear. About three months after surgery, Kinako's owner reported that the cat's left eye demonstrated what he defined as a complete resolution of signs.

To date, UC Davis has treated 15 dogs, two cats and one horse with this procedure that now offers a minimally invasive alternative for referring veterinarians who have been faced with treating nasolacrimal obstructions using conventional, more invasive and typically less successful methods.

A clinical trial is underway at the veterinary hospital to evaluate the procedure so it can become the standard-of-care for this otherwise frustrating disease complex.