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Pannus
Also know as superficial stromal keratitis, Ubbereiter’s
syndrome.
Clinical Signs
Most affected dogs have corneal lesions.
There are 2 basic types of pannus
1. Vascular – usually arise from the lateral limbus
2. Pigment
Most cases have a combination of the vascular and
pigmentary forms. The more active the pannus is the more blood vessel
reaction is present. Once the pannus has been treated the vascular
reaction reduces but pigment usually remains.
Some cases also develop corneal lipidosis – cloudiness
in the cornea. This may be the result of the corneal inflammation
but also may develop from the topical corticosteroid therapy.
Many cases also involve the third eyelid; the pannus
causes depigmentation of the third eyelid.
In rare cases we have seen erosion of the medial canthus.
Predisposing factors
1. Breed German Shepherds are by far the most commonly
affected breed. It is unknown why German Shepherds are so predisposed.
Other breeds affected are Greyhounds and Border Collies
2. Sunlight The pannus lesions are potentiated by
UV light. Most pannus lesions become worse in summer, and then less
severe in winter.
Diagnosis
Is usually straightforward based on the marked breed
predisposition, and the clinical signs.
Treatment of Pannus
1. Strong corticosteroid drops are required to treat
Pannus. Depending on the severity of the lesions, the frequency
and strength of the drops may vary. Care must be taken when using
cortisone drops on the eye. If something happens to the eye that
causes an ulcer or an infection, the cortisone drops can make the
problem worse. Unlike humans cortisone drops in dogs do NOT cause
glaucoma or cataracts.
2. In severe cases cortisone injections onto the eye
may be required. This treatment is only in dogs that are difficult
to treat or in very severe cases.
3. In most cases we also use topical cyclosporin.
We find this particularly useful in cases with pigmentary lesions,
and also when the third eyelid is inflamed. In cases with severe
pigmentary keratitis we have found that long term cyclosporin and
cortisone may reduce the amount of the pigmentary keratitis. A minimum
of 3 months of twice daily therapy is required.
4. Keeping the patient out of the sun will help reduce
the severity of the lesions, and will reduce how much cortisone
will be required to control the lesions.
Prognosis
Most cases can only be controlled rather than cured.
Long term therapy is required. If treatment is stopped, the lesions
will recur.
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