Nuclear Sclerosis (Lenticular Sclerosis)

What is it?

Nuclear (lenticular) sclerosis is a gradual hardening of the center of the lens. The lens keeps adding new fibers throughout life without growing larger, so the central fibers become compressed and dense. It is considered a normal aging change in middle-aged to senior dogs. It is not the same as a cataract: a cataract is white and opaque, blocks light from reaching the retina, and reduces vision, while nuclear sclerosis does not appear to affect vision much.

What signs should I watch for?

You may notice an even, bluish or gray, rounded cloudiness in the center of both pupils, often easier to see from the side or in dim light. Your dog should otherwise see and behave normally. Bumping into things, white spots in the eye, or other vision changes are reasons to have the eyes checked, since cataracts are also common in older dogs.

How is it diagnosed and treated?

Your veterinarian can tell nuclear sclerosis from a cataract during an eye exam: with nuclear sclerosis, the back of the eye can still be seen through the lens. No treatment is needed. Regular checkups help catch cataracts, which can be treated surgically, ideally early.

Can it be prevented, and what's the outlook?

• Because it is a normal part of aging, nuclear sclerosis cannot be prevented, and the outlook for vision is good.
• Many older dogs later develop cataracts too, but nuclear sclerosis does not cause them.