What is it? Who gets it? How do you treat it?
What is it?
Pannus is term for a group of ocular surface conditions that are characterized by chronic superficial keratitis. It often starts at the lateral aspect of the cornea and creeps across the corneal surface gradually. Corneal neovascularization, corneal pigmentation, and granulation tissue are all potential clinical exam findings.
Pannus can also affect the third eyelid causing depigmentation and inflammation of the nictitans. When just the third eyelids are affected, it is often called plasmoma.
Differential diagnoses for chronic keratitis include keratoconjunctivitis sicca (KCS), corneal ulceration, and chronic irritation from adnexal disease such as entropion, contact from an eyelid mass, or abnormal eyelashes. Ulceration should be ruled out with fluorescein staining and a Schirmer Tear Test should be performed to rule out KCS.

Pannus is thought to be an inherited condition in both German Shepherds and Greyhounds but can happen in any breed. Ultraviolet exposure may exacerbate the symptoms and make it more difficult to treat.
How do you treat it?
This condition is an autoimmune disease and treatment with immunomodulators long term is typically necessary. Steroids are often the first line of treatment to get the disease into remission. I often begin treatment with NeoPolyDex drops or ointment three times a day. Prednisolone acetate (1%) or dexamethasone drops are also an acceptable treatment options. Hydrocortisone will NOT be strong enough to control this condition. After beginning treatment, I recommend a recheck within a few weeks to assess the response to therapy.
Once the inflammation is controlled, I gradually begin to wean the topical therapy overtime and continue to recheck along the way to ensure continued control of the keratitis.
At the second visit, once I document improvement in clinical symptoms, I often start either Cyclosporine (drops or ointment) or Tacrolimus twice daily. I prefer to manage this condition long term with one of these medications and wean the steroid if possible because they are better for the ocular surface long term. Long term topical steroids can increase the risk of corneal degeneration and can be problematic if corneal ulceration develops in the future.
Ultraviolet (UV) blocking glasses for dogs such as Doggles or RexSpecs can be used to help decrease UV exposure in refractory cases.