We will continue our discussion on all things cataract in recognition of National Cataract Awareness Month by talking about the most common postoperative change that occurs after cataract surgery: the posterior capsule opacity.
A posterior capsule opacity is the presence of a hazy membrane (capsule) just behind the intraocular lens implant. This condition is sometimes referred to as “secondary cataract,” although the term is actually a misnomer.
The natural lens of the eye is contained within a thin membrane known as a capsule. When the adult cataract is removed, the anterior part of the capsule is opened to remove the cataract, but the posterior side of the capsule is left intact to support the intraocular lens (IOL) and prevent vitreous humor from entering the anterior (front) chamber of the eye.
Approximately 20% of patients, many times within the first two years, will develop haze on the membrane behind the IOL following cataract surgery which results in diminished vision. The vision may be blurred, hazy, or be associated with significant glare and loss of visual acuity. This is due to the growth of leftover lens epithelial cells on the capsule, which frequently remain following cataract surgery. In some cases, if the condition progresses significantly, vision may be worse than it was prior to cataract surgery. That is why this condition is sometimes referred to as “secondary cataract.” Cataracts, however, never recur following cataract surgery.
The posterior capsule opacity may be thought of as a scarring process in the capsule or membrane, which contained the natural lens (cataract) of the eye. The condition of posterior capsule opacity is not preventable, but, is treatable and nearly always restores or improves vision. Fortunately, with the YAG laser, treatment of posterior capsule opacity is safe, effective, painless, and can be performed as an outpatient procedure.
In this procedure, known as YAG laser capsulotomy, the hazy posterior capsule is removed from the visual axis (line of sight) after the eye has been dilated. The advantage of the laser is that it allows the surgery to be completed without making a surgical incision on the eye.
Following a YAG laser capsulotomy procedure, patients may resume normal activities immediately. Most patients may expect their vision to improve within a day following the procedure and should anticipate some “floaters” following this procedure for a few weeks time which then resolve. As with any eye procedure, patients should contact their eye surgeon immediately if visual acuity worsens or fails to improve
Although a YAG laser capsulotomy does pose some risk, overall the procedure is extremely safe. A small percentage of patients will experience an increase in the pressure in their eye after surgery. Generally this will last less than 72 hours and if necessary may be treated with a short course of eye drops. The most important risk of the procedure is retinal detachment. Statistical analyses suggest that the lifetime risk of retinal detachment following cataract surgery in the U.S. is about less than 0.1%. That number rises to about 0.2% following YAG laser capsulotomy. This point should be clearly understood by all patients who require the procedure. In general, patients should report symptoms of floaters, light flashes, and a curtain-like vision loss to their ophthalmologist immediately.
The YAG laser is another technological advancement that has assisted cataract patients in more fully enjoying their life following surgery. Prior to its development the only option available to eliminate the posterior capsule opacity was another trip to the operating room to surgically open the scarred capsule. This painless and safe procedure is a very effective way to allow you to enjoy continued good vision.
(Editor’s note: If you have questions about your eye health e-mail Dr. Barowsky at email@example.com and we’ll try to answer your questions here at Eye-Q.)