Chronic Superficial Keratitis, in Dogs
Pannus is an immune mediated corneal disease primarily found in the German Shepard breed although other predisposed breeds include Greyhounds, Huskies, and Dachshunds. Other breeds reported to have problems with pannus include Poodles, Border Collies, and Labrador Retrievers. Ultraviolet light and altitude influence the severity of the disease.
Pannus is a progressive, non painful, inflammatory disease of the cornea, conjunctiva, and sometimes the third eyelids (when affecting the third eyelid, it is termed "atypical pannus" or "plasmoma").
Variable proportions of pigmentation, corneal vascularization, granulation tissue, and cholesterol deposits characterize Pannus. The corneal changes usually begin on the lower outside surface of the eye. Both eyes are affected, though the diseased regions may be asymmetric. Some dogs also have dry eye problems. As the disease progresses, blindness can develop. The cause of Pannus is not well understood, but several factors are involved: The breed incidence suggests a heritable predisposition. Additionally, UV (ultraviolet) radiation plays an important role as an inciting and propagating factor. Dogs living at high altitudes and low altitudes are more severely affected. Also, autoimmune factors and possibly genetics play a part.
GOALS OF MANAGEMENT AND CARE:
- LIFE LONG therapy is necessary. Steroid eye drops or ointments are usually used, in addition to topical tacrolimus solution or ointment. The steroid and tacrolimus work together to help decrease corneal scarring and vascularization. Corneal pigmentation is especially improved by tacrolimus medication.
- Our goal is to begin treatment aggressively with both medications and to slowly decrease the dose frequency. Once the disease is under control, then annual re-examinations are required.
- When medication alone fails to control Pannus, then surgical and radiation treatment is recommended, but these therapies are rarely used.
- Sub-conjunctival steroid injections are sometimes used initially to achieve high corneal concentrations. They may also be used to control flare-ups.
- Owners must contact veterinarian if eye pain develops, which could mean that a corneal ulcer has occurred. If an ulcer is present, the topical steroid would need to be stopped.