What are the symptoms of a secondary cataract (cloudy capsule)?

As a practicing ophthalmologist, the symptom that usually tips me off to look for a cloudy capsule is when patients start to experience a decrease in their reading vision. There is also often a corresponding in the quality of vision at night, especially noticeable when driving, accompanied by an increase in glare around lights.

A "secondary cataract," perhaps better known as a "clouded capsule" or "posterior capsular opacification" is not really a cataract at all. It is the loss of crystalline transparency of the "wrapping" or "envelope" of the natural lens that is left behind deliberately with removing the cataract/discolored natural lens. The replacement lens (IOL) is inserted into this envelope to provide a stable, secure container for the soft plastic artificial lens implant. Within a few weeks the capsule shrinks and sticks firmly to the new lens implant, making it a part of your body.

The problem is that while the capsule starts out soft, elastic, and as transparent as cellophane, it doesn't stay that way: it starts to lose these qualities and very gradually clouds up. When this gets bad enough, a YAG laser procedure can be done to create a central hole in the capsule behind the IOL, allowing a clear transmission of an image. The peripheral capsule is left in place 360˚ since this is keeps the IOL securely in place.

If you wait long enough, most all capsules will cloud up although there is a great variability in how soon it starts to affect your vision. Once a YAG capsulotomy procedure is done, the vision returns almost instantly to what it was before the capsule began to fog. It is extraordinarily unlikely to recur and require another YAG procedure in the future.

_Written by J. Trevor Woodhams, M.D. - Chief of Surgery, Woodhams Eye Clinic