Vision Eye Institute specialises in cataract surgery for humans, but did you know that your pets can get cataracts as well?
‘Cataract’ is defined as any opacity of the lens of the eye that clouds clear vision. Today, cataract surgery is regarded as a very successful procedure. But what if an individual is slowly losing sight because of a cataract and is unable to tell anyone about it?
Elephants, horses, pandas, seals and orangutans can all develop cataracts. Although the incidence of cataracts in cats is surprisingly low, dogs are commonly affected by cataracts, particularly purebreds. Certain breeds are more susceptible than others – Bichon Frise, Boston Terriers, Poodles, Labrador Retrievers and Golden Retrievers to name a few.
Every dog will eventually develop what is called nuclear sclerosis. This is a change in the density in the centre of the natural lens (the nucleus), and appears as a bluish-grey haze. It occurs as a dog grows older, usually developing after the age of 6. While nuclear sclerosis causes light to scatter, it does not necessarily impair the vision of a dog (unless it is unusually dense).
Because all dogs will develop nuclear sclerosis, it is sometimes difficult to diagnose a cataract simply by looking at the eye. If the pupil of one or both eyes appears to be white or a more dense blue, this could indicate cataract is present.
The first sign of cataracts in a dog may in fact be if he or she becomes unusually clumsy – walking into walls, tripping, misjudging distances or not recognising a previously familiar face.
There is no single cause of cataract in dogs. Most are due to genetics (hence, purebred dogs being more susceptible to cataract). However, they can also develop as a result of diabetes, a toxic reaction in the lens, inflammatory disease or nutritional deficiencies.
While a cataract is painless, it will affect sight and a dog may eventually become blind in one or both eyes.
As with humans, there is only one cure for cataracts – cataract surgery. The procedure and equipment used is the same as when performing cataract surgery on humans. Unlike humans, a dog must wear a cone collar for up to two weeks to prevent it from scratching or traumatising the eye.
Vision should improve in the days and weeks following cataract surgery. However, the activities of a dog should be limited for several weeks after cataract surgery. Oral medications and eyedrops or ointments will also be prescribed.
Until the recent development of a canine intraocular lens (IOL) , the cloudy lens was simply removed. This left the dog with normal mid-to-long distance vision, but poor close-up vision. The option of implanting an artificial lens to replace the natural lens can restore full vision to the dog.
Just as humans requiring cataract surgery must be referred to an ophthalmologist, a suitably qualified veterinarian must perform cataract surgery on dogs. Your local vet will be to refer you to veterinary ophthalmologist, who has undertaken further specialty training.
For more information about cataracts and cataract surgery for humans, visit our cataract surgery page.