Cataracts are a leading cause of visual impairment in dogs and frequently progress to cause total blindness. Vision of affected dogs can often be restored to a normal state by surgically removing the abnormal lens and substituting an artificial lens in its place.
A cataract is opacity or clouding of the lens within the eye. The lens' function is to focus light rays on the retina, and cataracts decrease vision by interfering with light reaching the retina. Advanced cataracts are a leading cause of blindness in dogs and are generally recognizable by pet owners as a decrease in the dog's vision or by a cloudy, whitish-blue appearance to the eye. Cataracts must be distinguished from a normal aging change in the lens termed "lenticular sclerosis," which causes a bluish appearance to the eye but generally does not interfere with vision.
Currently, the only effective treatment for cataracts is through surgical removal of the defective lens. Lens removal is done under general anesthesia by making an incision in the eye and using special equipment to ultrasonically fragment and remove the diseased lens material. In most cases, an artificial intraocular lens is implanted to replace the diseased lens.