Breed Occurrence
The Basenji dog is pedisposed to develop PPM and so may develop associated
cataract.
Other breeds in which inherited cataracts have been reported include :
Afghan , Australian terrier, Boston terrier, Chesapeake Bay retriever, Cocker
spaniel, Entelbucher Mountain dog, German Shepherd dog, Golden Retriever,
Labrador Retriever, Norwegian Buhund, Old English Sheepdog, Poodle (Miniature
and Standard), Rottweiler, Schnauzer (Miniature), Springer Spaniel (Welsh),
Staffordshire Bull Terrier, West Highland White terrier
It is also suspected in the following breeds:
Beagle, Pointer, Toy poodle, Sealyham terrier and wire-haired Fox terrier
Diabetic cataracts can progress very rapidly and mature in 2-4 weeks, but
most progress slowly.
Cataracts may also be associated with other ocular diseases such as
progressive retinal atrophy. In such cases treating the cataract (eg by
removal of the affected lens) will not improve vision.
Treatment
Cataracts may be left in situ
providing the animal retains reasonable vision, especially in late-onset senile
cataracts
Use of a mydriatic may
improve vision in the early stages.
Several
surgical procedures can be used to treat cataracts including :
- Extraction
- Extracapsular - remove all
the lens except the posterior capsule
- Intracapsular - remove the
entire lens including both capsules
- Phaecoemulsification - ultrasonic shattering of the lens tissue then
removal by irrigation and aspiration
- Discission - removal of liquid cataracts (young animals) by aspiration
through an incision in the anterior capsule
Surgical treatment is sometimes
followed by complications.such as uveitis, and retinal detatchment if
intracapsular extraction has been done.
Following
extraction it is possible to replace the totally removed lens with a synthetic
replacement lens. Intraocular lenses of 40D power are used in dogs.
Cataract
surgery should not be performed in the following patients:
- The affected eye is blind for other
reasons than the cataract eg concurrent retinal disease - may require
electroretinography to rule out this possibility, not just a positive
pupillary light reflex
- Patients with active uveitis