Cataracts may be :
Cataracts are often described according to their stage of development :
There are many possible causes of cataract including :
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.
The structure of the lens changes as the cataract matures resulting in leakage of lens contents into the surrounding aqueous which can result in uveitis or glaucoma.
Lens luxation is another potential complication as the lens swells during cataract development
Diagnosis of cataract is confirmed by direct visual appraisal using a light source or ophthalmoscope
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 :
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 prognosis can be good for untreated, slowly progressive cataracts, and many animals do not go on to develop serious impairment of vision or blindness during their lifetime
The prognosis can be good for animals subject to surgery.
Long term problems
Long term problems in untreated patients include the risk of secondary uveitis and glaucoma
Long term problems in surgically treated patients include residual visual impairement or blindness due to post-operative complications, such as retinal detachment
Updated January 2016