Immune mediated keratitis (IMMK) occurs when the immune system has been stimulated to attack corneal tissue leading to inflammatory changes within those tissues. Like many other immune-mediated diseases that can affect other tissues in the body, the underlying mechanism of IMMK is not well understood. Changes to the cornea can include color changes due to pigmentation, blood vessel formation, and the formation of opacities. The appearance of each case will vary and may also be dependent on the type of IMMK with which your pet has been diagnosed. Other signs of IMMK may also include reddening of the sclera (white tissue around the cornea), excessive discharge, or squinting; however, these signs can be nonspecific and are seen with a variety of other ophthalmic conditions as well.
Chronic superficial keratitis (or Pannus) and superficial punctate keratitis are two examples of IMMK in the dog. Pannus can be seen in many breeds but has been strongly associated with the German Shepherd and the Greyhound. It manifests as pigmentation and vascularization of the cornea in a characteristic pattern that starts at the corner of the cornea and moves across it. Superficial punctate keratitis has been described in the Shetland Sheepdog and the long-haired Dachshund, but, like Pannus, can be seen in any breed. Superficial punctate keratitis often looks like grey, opaque dots on the cornea, prompting owners to bring their pet into the ophthalmologist. In both forms of IMMK, the patient may or may not be uncomfortable due to irritation and possible corneal ulceration.
The mainstay of therapy for any IMMK is topical medications to stop inflammation and suppress the local immune system. Usually one or two types of medications are used depending on the type of IMMK and the severity of the symptoms. One group is immunomodulatory medications and include cyclosporine and tacrolimus. The other group is steroid medications and include prednisone or dexamethasone. Most dogs with IMMK do very well with medical management; however, medications are often needed very long term or, in some cases, permanently. The veterinary ophthalmologist will recommend a treatment plan for your pet’s specific needs. They will also recommend recheck exams to monitor your pet’s condition. The goal of therapy for IMMK is to allow your pet to be on the lowest amount of medications needed to keep their IMMK controlled. These recheck examinations will be very important as medications will often be adjusted during these visits.
Please call our office if you notice any change in the appearance of your pet’s eyes, such as redness, or your pet seems uncomfortable (squinting or holding the eyes closed).Back to Previous Page