What is the Capsule?

The natural lens of the eye is held in place by a thin clear membrane called the lens capsule. The capsule completely surrounds the lens and separates it from the thick fluid in the back of the eye, called the vitreous, and the thinner fluid in the front of the eye, called the aqueous.

Posterior Capsule Opacity

Cataract Surgery Effects the Capsule

Cataract surgery is necessary when the natural lens become cloudy and must be removed. When cataract surgery was originally performed, surgical techniques were not as refined as today, and both the natural lens and the capsule were removed during surgery. Newer techniques allow the capsule to remain in the eye and hold the implanted lens (or intraocular lens, IOL) in place. Leaving the capsule in place during surgery is a great advancement because it allows the vision after surgery to be more stable and provides for less surgical complications.

Sometimes the posterior, or back, portion of the capsule becomes cloudy after cataract surgery. This is known as a secondary membrane or a cloudy posterior capsule. The reasons for this cloudiness are unknown. If the posterior capsule becomes so cloudy that it becomes symptomatic and affects vision, then a laser capsulotomy is performed.

What is a Capsulotomy?

A capsulotomy is a procedure in which an opening is created in the center of the cloudy capsule. The opening allows clear passage of the light rays and eliminates the cloudiness that was interfering with the vision. A laser beam is used to create this opening. This procedure is painless, very safe and typically the results can be seen immediately. For capsulotomy, as with any surgery, rare complications can occur, such as swelling or retinal detachment. These complications can cause loss of vision.

A cloudy capsule will may times appear the same way as the original cataract. The vision is cloudy or hazy and the patient is heavily bothered by glare. In fact, vision is so similar that some patients think that the cataract has come back. This is impossible, cataracts cannot return once the natural lens has been removed.

Laser opens the posterior cloudy capsule

If your vision is getting worse after cataract surgery, it could be that your capsule is becoming cloudy. Your eye doctor should give you a thorough eye examination to determine the cause of your vision loss. If your capsule is becoming cloudy, your eye doctor can then determine whether a laser capsulotomy is necessary to improve your vision.