Cataract Surgery Complications

By Chris A. Knobbe, MD

Cataract surgery complications are few, but one of the most common is posterior capsule opacity (PCO), which you may have if your vision is cloudy or blurry after cataract surgery. A PCO is a hazy membrane (capsule) just behind the artificial intraocular lens (IOL) that was implanted during your cataract surgery to replace your eye's natural lens.

Although some people call this condition a "secondary cataract," it is not really a cataract. Once a cataract is removed, it does not come back.

Other cataract surgery complications can include eye inflammation, infections or a dislocated intraocular lens.

Why Is Posterior Capsule Opacity a Common Cataract Surgery Complication?

During cataract surgery, your surgeon will remove the cloudy natural lens of your eye (cataract), replacing it with an intraocular lens implant.

When the cataract is removed, your surgeon makes every attempt to maintain the integrity of the capsule that contained the natural lens so the new lens can be placed within it. Normally your vision after cataract surgery should be very clear.

However, about 20 percent of patients with intact posterior capsules have haziness of the capsule, so vision is blurry.

This occurs because lens epithelial cells remaining after cataract surgery have grown on the capsule. In some cases, if the condition progresses significantly, your vision may be worse than it was before cataract surgery.

Treating Posterior Capsule Opacity

Fortunately, a YAG laser can treat posterior capsule opacity safely, effectively and painlessly. This procedure, known as YAG laser capsulotomy, often can be performed in your doctor's office.

YAG laser capsulotomy involves just a few simple steps:

• Usually the eye is dilated before the procedure, with dilating eye drops.
• A laser removes the hazy posterior capsule from your line of sight without making an incision or "touching" the eye.
• Many ophthalmologists recommend anti-inflammatory eye drops following the procedure.

The procedure takes only a few minutes and is entirely painless; nor does discomfort occur post-operatively.

You must remain still during the procedure, however. Very uncooperative patients, such as children and mentally disabled people, may require sedation.

Following a YAG laser capsulotomy, you may resume normal activities immediately. You may experience some floaters afterward. These will likely resolve within a few weeks.

Most people can expect their vision to improve within a day. As with any eye procedure, however, call your eye doctor immediately if vision worsens or fails to improve.

YAG Laser Capsulotomy Risks

Although a YAG laser capsulotomy poses slight additional risk, overall the procedure is extremely safe. The most important risk is that the retina can become detached from the inner back of the eye.

Statistics suggest that the lifetime risk of a detached retina as a cataract surgery complication in the United States is about 1 percent. That number rises to about 2 percent after YAG laser capsulotomy. It is important to be aware of this cataract surgery risk.

Dislocated Intraocular Lenses

Another example of cataract surgery complications is malpositioned or dislocated intraocular lenses. You may see the edge of the lens implant, or you may even develop double vision. If the intraocular lens becomes too badly dislocated, your visual acuity could decrease substantially.

How can an IOL become malpositioned or dislocated?

In most cataract surgeries, the intraocular lens is placed inside the "capsular bag," which contains the cloudy natural lens or cataract of the eye.

Ophthalmologists make every attempt to maintain the integrity of the capsular bag so that the intraocular lens can be positioned correctly within it. But the capsular bag is extremely thin — approximately the thickness of a single red blood cell — and can sometimes rupture or break.

Also, the capsular bag itself may dislocate due to weakness or breakage of the fibers (zonules) that hold it in place, resulting in a condition known as zonular dialysis. This condition places you at risk of malpositioning or dislocation of the lens implant.

Even without underlying complications, intraocular lenses can still dislocate — especially if one of the springy "arms" holding the lens in place is positioned improperly inside the capsular bag or becomes malpositioned later on.

When an intraocular lens implant is malpositioned or dislocated, your cataract surgeon can probably reposition it in a second procedure. In some cases, the lens implant must be sewn in place, or another type of lens must be implanted.

If IOL dislocation occurs following a recent cataract surgery, repositioning the lens should be done soon. This is because lens implants begin to "scar" into place approximately three months after original implantation and can become much more difficult to remove.

If you do experience a malpositioned or dislocated intraocular implant, your chances of a good outcome following a second procedure are very good if you and your surgeon take action promptly.

Other Cataract Surgery Complications

Cataract surgery is one of the most successful procedures in all of medicine. But potential cataract surgery complications range from minor eye inflammation to devastating vision loss. The risk of severe vision loss is very rare and may occur as a result of infection or bleeding inside the eye.

Some cataract surgery complications occur quite a while later. For example, retinal detachment can occur months or years after a perfectly successful cataract procedure.

If your vision becomes cloudy from a "secondary cataract," you may require a YAG laser capsulotomy.

Most patients with retinal detachment have a good outcome if they see their ophthalmologist when symptoms first begin and treatment is done immediately. However, a small percentage will have substantially and permanently reduced vision. Be sure to report floaters, light flashes and a curtain-like vision loss to your ophthalmologist immediately.

But most complications are minor and may include:

• Swelling of the cornea or retina.
• Increased pressure in the eye (intraocular pressure).
• Droopy eyelid (ptosis).

Minor complications usually clear up with medications and more healing time.

Vision After Cataract Surgery

More than 98 percent of cataract surgeries are successful, without surgical complications, and more than 95 percent of patients have improved vision.

People whose vision fails to improve often have underlying eye disorders, such as age-related macular degeneration, diabetic retinopathy and other eye conditions. Some of these individuals may benefit from other procedures or from low vision aids.

Other Resources:

A systematic overview of the incidence of posterior capsule opacification. Ophthalmology. July 1998.

Biostatistical analysis of pseudophakic and aphakic retinal detachments. Seminars in Ophthalmology. 2002.

Retinal breaks and detachment after neodymium: YAG laser posterior capsulotomy: Five-year incidence in a prospective cohort. Journal of Cataract and Refractive Surgery. 2004.

[Page updated June 2009]