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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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