Dogs can get cataracts in their eyes just like humans can. Cataracts in dogs affect a structure in the eye called a lens. The lens is the globoid structure in the eye filled with a clear jelly-like substance. The lens is very important for sight, as it focuses light onto the retina to create an image that is in turn recognised by the brain. In a cataract, the normally clear lens undergoes changes that cause it to become opaque. The more opaque the lens becomes, the less it is able to fulfil its role in sight.
In most cases, we cannot identify the cause for cataracts in older dogs, and it is thought that genetics play a role. Some breeds, such as Bichon Frise, have a genetic predisposition to developing cataracts at a younger age. Identifiable causes include glaucoma secondary to diabetes, drug reactions or trauma.
A cataract develops over several months to years, and causes a foggy appearance in the eye. Small cataracts may have minimal effects on vision, however large, mature cataracts usually cause blindness and the pooch may be seen to bump into objects. A separate change, called Nuclear Sclerosis, is common in older dogs and can give the dog's eyes a foggy appearance without causing blindness as cataracts do. Damage and scarring to the cornea can also give the eyes a foggy appearance also, and should not be confused with cataracts. Most veterinarians can distinguish cataracts from these other conditions, however this may be difficult in the case of early cataracts.
Options for cataract treatment in dogs are limited. In some cases, certain cataract drops for dogs may be prescribed to improve vision. Surgery to remove the lens and potentially replace it with an artificial lens is the only effective treatment for cataracts, and this is performed by veterinary opthalmologists. Surgery usually results in acceptable vision, although complete vision is not accomplished in many cases.
Do you know of any dogs that had cataracts? What was the treatment? Share with us in the comments!