AN OASIS FOR CANINE DRY EYE DISEASE
As you may know, Dry Eye Disease (Keratoconjunctivitis Sicca), is a disease of the tear secreting glands that result in reduction or lack of tear production. The superficial layers of the eye, including the cornea, conjunctiva, as well as the eyelids depend on tears for nutrition and protection. Without adequate tears, these structures are highly susceptible to disease.
The tear (lacrimal) gland is located above each eye and is responsible for the production of the tear film. This tear film is compromised of three layers:
An outer oily layer, produced by the meibomian glands
The large aqueous layer, secreted by the lacrimal and accessory lacrimal gland
The basal mucus layer, produced by the conjunctival goblet cells
In a normal eye, all these layers work together in a balanced union for the health and protection of the eye. Also, there are important antibacterial enzymes present within tears that keep our eyes clear of infection.
Some animals, as well as humans have depressed lacrimal gland function that renders them lifelong dry eye patients. As the disease progresses, blood vessels and pigment invade the cornea, in which varying degrees of visual impairment may occur if not treated aggressively. When treating these KCS patients, topical and sometimes oral medications are necessary to provide comfort, as well as to “jump start” the depressed lacrimal gland. Most medications have to be prescribed by a doctor, but there some OTC (over the counter) topicals that can assist in lubricating the eyes.
In efforts to reach out to our local community’s youth, Atlanta Veterinary Eye Clinic granted a young student, Dhwani Kumar, the opportunity to work with us for her yearly science fair project. Dhwani and her father Dr. Sai Kumar love spending time together in their shared interest of science. So for her research project, she decided to explore the possibility of topical lubricants that could be utilized in human and animals for treatment of dry eye disease. They both agreed that AVEC was a great place to get more information on the subject. Dhwani and her father both visited the clinic several times to run trials with some of the leading OTC topical lubricants on three volunteer canine patients at AVEC.
Dhwani wanted to test the longevity of five saline based topical lubricants: Blink, Optive, Systane, Genteal, and Soothe XP. To challenge the endurance of each product, we used the following steps:
We first used a Schirmer tear test on each canine’s eye to determine their tear production in a 60 second time frame. This test requires a thin measuring strip of paper called a Schirmer tear test, to be latched to the bottom eyelid to measure the tear production of each eye. We notated the results.
We used a Fluorescein stain with each topical lubricant tested on each eye. Fluorescein is a painless diagnostic stain that we used to visualize the coating of each solution used. We blinked the eyelids three times to ensure the spread over the total cornea.
Then utilized slit lamp biomicroscopy to visualize the “break up time”, or the time it took for the stained solutions to leave the cornea. The slit lamp biomicroscope used is a hand held, high powered illuminating ophthalmic instrument.
We timed how long the different solutions stayed on the eye, and documented each one individually.
Finally we had a winner for the product that had the most endurance in coating the cornea, and staying on the eye the longest. Congratulations to: Soothe XP.
Soothe XP solution notably has the best longevity and endurance amongst the other products tested.
We would like to thank Dhwani Kumar and her father Dr. Sai Kumar for the great experience, and the research efforts that AVEC can share with our patients.
We also would like to thank the volunteers that participated in this research project.
Ms. Gilda Jones & “Honeybear”
Ms. Vanessa Smith & “Zeus”
Dr. Powell-Johnson & “Hattie Mae”