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What Is A Secondary Cataract?

Sometimes, people who have their vision successfully restored with cataract surgery experience a second decline in their eyesight several weeks or months after their cataract procedure.

In these cases, people sometimes worry that their cataract has "grown back."

Explaining what causes this vision loss requires a brief discussion of eye anatomy and cataract surgery:


A YAG capsulotomy to treat a secondary cataract takes only a few minutes and typically never needs repeating.

The crystalline lens of the eye is enclosed in a clear membrane called the lens capsule. A significant portion of the lens capsule that's in front of the lens is removed during cataract surgery to enable the surgeon to gain access to the cloudy lens (the cataract), break it up, remove it, and replace it with a clear intraocular lens (IOL).

The posterior portion of the lens capsule (the part behind the lens) is left intact during cataract surgery, and the IOL is implanted directly in front of it.

In a small percentage of people who have cataract surgery, the posterior lens capsule becomes cloudy several months or even years after surgery. The medical term for this is posterior capsular opacification (PCO). Other commonly used terms for PCO include secondary cataract or after-cataract.

Vision lost from a secondary cataract can be restored with a procedure called a YAG laser capsulotomy. In this in-office procedure, your surgeon uses a specialized laser to create a clear "window" in the posterior lens capsule, which quickly restores visual acuity. The YAG capsulotomy takes only a few minutes and typically never needs repeating.

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