William R. Pritchard Veterinary Medical Teaching Hospital

Clinical Studies

Mesenchymal Stem Cell Therapy for the Treatment of Dry Eye in Dogs

Investigator(s): Dr. Kathryn Good, Dr. Christopher Murphy, Monica Motta

Purpose and background: Dry eye (keratoconjunctivitis sicca) is a common ocular disease in dogs that leads to discomfort and vision loss. Mesenchymal stem cells (MSCs) have been proven to reduce inflammation and differentiate into a variety of cell types. Since the most common cause of dry eye in dogs is an immune-mediated inflammatory response targeted against tear producing glands, this study was designed to determine if treatment with MSCs will cause local, long term control of tear gland inflammation and dry eye.

Procedures: Candidates for this clinical trial are those dogs whose tear production is well controlled on cyclosporine or tacrolimus. Serial Schirmer tear tests will be performed. This is a minimally invasive procedure to measure tear production.  Patients undergo a minor surgical procedure during which a small sample of fat is obtained from the abdomen in order to harvest the stem cells. Under a separate sedation, these stem cells are injected into the lacrimal and third eyelid glands.

Benefits: If MSCs injected into the tear producing glands of dogs with immune-mediated dry eye results in increased tear production, this procedure may remove the need for life long topical supplemental therapies.

Association Between Blepharitis, Topical Oil-based Ophthalmic Medication, and Presence of Malassezia in Periocular Skin of Dogs

Investigator(s): Georgina Newbold, Dr. David Maggs, and Dr. Catherine Outerbridge  

Purpose and background: Malassezia pachydermatis is a yeast commonly associated with skin and ear infections (otitis externa) in dogs. This yeast likes lipid or oils, and its growth is improved by a lipid-rich medium. Therefore, it is probable that topical application of oil-based eye medications may promote growth of Malassezia on the eyelid skin due to a change in the composition of the lipids in the microenvironment of the periocular skin. This study is designed to determine the relationship between application of eye medications and presence of Malassezia (yeast) organisms in the eyelid skin of dogs with or without inflamed eyelids.  

Procedures: Samples will be collected using a strip of clear adhesive tape that will be briefly placed in contact with the eyelid skin, removed, and attached to a glass slide. This is a painless procedure routinely used for examination of patients with skin disease.  

Benefits: Establishing a relationship between eye medications and growth of Malassezia may lead to alternate preparations being prescribed for patients with a known history or high risk of skin infections.  Your dog will be checked for the presence of Malassezia at no cost to you. If your dog is identified as having an overgrowth of Malassezia, treatment may improve your dog’s comfort.

Comparing tear quality and production in healthy dogs versus dogs with atopic dermatitis

Investigator(s):  Dr Dani Hoolahan, Dr Catherine Outerbridge, Dr David Maggs

 Purpose and background:  Furiani et al (2011) stated that dogs with atopic dermatitis have dry eyes. However, despite an extensive literature search we have not found evidence to support this claim. The purpose of the study is to investigate this claim by comparing tear production and quality between dogs confirmed to have atopic dermatitis and healthy dogs. If the claim is supported, dogs with atopic dermatitis may benefit from supplementation with artificial tears or lacrimogenic drugs as part of their treatment protocol.

Procedures:  We will be performing a Schirmer tear test, measuring tear film break up time, and performing meibometry.  These are all minimally invasive procedures that allow us to measure and sample tears produced from your dog’s eyes. The dog remains awake and the procedures are non-painful. 

 Benefits: If dogs with atopic dermatitis have dry eyes, they may benefit from supplementation with artificial tears or lacrimogenic drugs