Treatment of Canine Keratoconjunctivitis Sicca with an Aqueous Formulation of Cyclosporine

Purpose

To evaluate the safety and effectiveness of a new formulation of a topical drug, cyclosporine, currently used to treat Keratoconjunctivitis Sicca (KCS), commonly called "Dry Eye."

Background

The causes of KCS include inherited, age-related, breed-associated and drug-induced. In most affected dogs the disease is incurable, requiring lifelong topical medications and, on occasion, surgery. KCS results in cummulative and often irreversible damage to the cornea leading to corneal scar, vascularization, pigmentation and vision loss. In addition, the disease can be chronically painful. Treatment has included topical artificial tear supplements, topical cyclosporine or tacrolimus and parotid duct transposition. The current standard of care would be topical cyclosporine or tacrolimus every 12 hours for the life of the dog. The current formulation of these medications are not water soluble and must be made in an ointment or oil-based form and are often compounded individually for each dog. Unfortunately, this formulation has limited bioavailability. The goal of this study is to evaluate a water-soluble form of cyclosporine which would be more user friendly for the owner, easier to administer and hopefully more bio-available, improving owner compliance and patient response. The water-soluble test drug will be compared to the same concentration of cyclosporine compounded in a traditional manner and delivered in an oil-based vehicle. If this formulation of cyclosporin is effective, it will have implications for other immune and inflammatory corneal diseases in animals (dog, cat, horse) and humans and may have benefit for cyclosporin- responsive intraocular diseases such as immune-mediated uveitis (human, dog, horse).

Inclusion Criteria

To qualify for enrollment in this study, dogs must:

  • Have confirmed diagnosis of KCS
  • Not be currently being treated with a cyclosporine-type drug

Study Design

  • Initially, a routine complete ophthalmic examination will need to be performed to determine the patient's eligibility. This includes an evaluation of ocular discharge and comfort, menace and pupillary light responses, penlight examination, slitlamp examination, Schirmer Tear Test (STT), determination of the Tear Break-up time, flourescein stain uptake, determination of intraocular pressure and indirect ophthalmoscopy following dilation of the pupils.
  • If deemed eligible, you are required to fill out a questionaire, and your dog will be randomly assigned to a treatment group (the study drug or 1% cyclosporine). Both medications are to be administered every 12 hours for the duration of the study. The veterinarian will be blinded during the course of the study,i.e. will not know which drug your dog is receiving.
  • A routine STT will need to be performed on Day 7 and 14 which can be performed at OSU or at your local referring veterinarian.
  • A 1 month and 2 month recheck will need to be performed at OSU. During these visits you will need to fill out a questionaire, and a routine complete ophthalmic eximation will be performed on your dog.

Client Compensation

  • All study medication will be provided at no cost
  • All examination charges following study enrollment will be covered by the study

Contact

Dr. David Wilkie, wilkie [dot] 1 [at] osu [dot] edu or Dr. Anne Metzler, metzler [dot] 134 [at] osu [dot] edu, or call 614-292-3551 for further information.