Keratoconjunctivitis sicca (‘Dry Eye’)
‘Dry eye’ is a common eye disease of
dogs. It occurs when insufficient tears (which are essential to keep
the eye moist and healthy) are produced from the tear glands and is
diagnosed by measuring tear production using a ‘Schirmer Tear
Test’.
In most cases, both eyes are affected and common
signs of ‘dry eye’ include:
- Recurrent conjunctivitis
- A sticky grey/white/green discharge from one
or both eyes
- Clouding or dullness of the surface of the eye
(the cornea)
- Discomfort
– the animal may blink more than normal or rub at its eyes
Treatment
The main aims of treatment are to keep the eyes
comfortable, free from infection and to preserve vision by increasing
tear production or by giving artificial tears. Most cases of dry
eye will need lifelong management. Treatments will vary from case
to case and depending on the suspected cause of the ‘dry eye’.
However, treatment options usually include the following:
-
Medication to stimulate tear production.
In most cases, the first-line treatment is cyclosporine eye ointment
(OptimmuneTM).
Optimmune treats the underlying cause of dry eye (destruction of the
tear glands by the body’s immune system) and as such is the
best treatment in mild to moderate cases. It is usually very
effective, but it needs to be given twice daily every day, and
lifelong treatment is usually required. If Optimmune is
ineffective, we will sometimes prescribe a stronger solution of
cyclosporine (cyclosporine in corn oil).
-
Artificial tears. These include drops,
gels and ointments to keep the surface of the eye moist and prevent
evaporation of tears. These do not treat the underlying cause, but
instead help to replace the tears that are not being produced.
-
Surgery. Surgery (Parotid Duct
Transposition, PDT) is usually only considered as a last resort
(i.e. if medical management fails) and is not without complications.
Surgery involves moving a salivary duct from its usual opening into
the mouth to inside the lower eyelid.
Saliva is then secreted onto
the surface of the eye and acts to ‘mimic’ tears and
keep the surface of the eye moist. Note that even after surgery,
lifelong management may still be needed to keep the face clean and
treat any complications that can occasionally be caused by saliva
being present in the eye instead
of tears.
Whatever treatment is advised, management will
usually be needed for the duration of the dog’s life and
regular visits to the ophthalmologist or your own vet will still be
needed. During these visits, the health of the eye will be checked,
tear production will be reassessed and any side effects of the
treatment strategies will be monitored.
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