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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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