An opacity involving the lens of the eye that prevents light from reaching the retina is termed a cataract. Cataracts can be inherited (juvenile cataracts) or might develop secondary to eye trauma, infections, or metabolic disease, such as diabetes mellitus.
As lens opacity increases, the amount of light allowed to reach the retina is diminished, and partial blindness ensues. Cataracts can also predispose to rotation or luxation of the lens. Such lens movement can disrupt normal fluid flow within the eye and lead to secondary glaucoma.
True cataracts must be differentiated from lenticular sclerosis seen in older pets. Lenticular sclerosisis a lens opacity caused by a normal hardening of the lens material due to age. It is a normal aging change seen in some dogs, and rarely leads to loss of sight as can occur with cataracts.
As a result, no specific treatment is required for most cases of lenticular sclerosis. Lenticular sclerosis and cataracts can be differentiated with an ophthalmologic examination performed by a veterinarian.
Treatment for cataracts usually involves surgical removal of the offending lens. A less invasive surgical technique for cataract removal is called phacofragmentation.
This procedure employs the use of ultrasound to break up the lens material into small pieces, which can then be drawn or sucked out of the eye using special instrumentation. Once cataracts are removed, vision is effectively restored in the affected pet.