October 12, 2007
Meet Jai-Li, who is now a 3-year-old, female spayed, Chinese Crested dog (see photos). We first met Jai-Li when she was only 3 months old! She came to Northwest Animal Eye Specialists for evaluation of a severe problem affecting her left eye. Signs were present from the time Jai-Li opened her eyes.
Jai-Li's diagnosis was severe, congenital, and inherited keratoconjunctivitis sicca (KCS or "dry eye"). (See the KCS section of this website if you would like to read more about this condition.) Congenital KCS is one of the less common types of KCS. To give you an idea of how severe Jai-Li's condition was, normal tear production is greater than 15 mm of wetting (on a tear test strip) in 60 seconds. Jai-Li had no more than 3 mm of wetting in a minute! Despite treatments, without adequate tear production Jai-Li could not be kept comfortable and within 6 months she had absolutely no tear production.
Unfortunately, this type of KCS is usually poorly responsive to therapy. It is due to underdevelopment of (or lack of) tear-producing glands and there is typically no way to restore tear production. So at 9.5 months of age, Jai-Li had major surgery called parotid duct transposition (PDT). In this surgery, the duct from the parotid salivary gland is isolated and repositioned next to the eye. So the eye is now wet but from saliva rather than tears. It is a strange concept but can do wonders for eliminating pain from severe dry eye and for preserving vision. When PDT patients see/smell food, they cry!!
Parotid duct transposition surgery is not recommended for most of our KCS patients. Most cases are medically manageable and this is the preferred route of management. It is a major surgery and is not without risk for complications. Furthermore, it does not always eliminate the need for long-term medical therapy. For instance, Jai-Li is still on some medications to manage some mineral deposits on her eye. Saliva is similar to tears and is lubricating, but it is not identical to tears so there can be issues that require management.