Cataract surgery

Surgery Overview

A cataract is a painless, cloudy area in the lens of the eye. The lens is enclosed in a lining called the lens capsule. Cataract surgery separates the cataract from the lens capsule. In most cases, the lens will be replaced with an intraocular lens implant (IOL). If an IOL cannot be used, contact lenses or eyeglasses must be worn to compensate for the lack of a natural lens.

See a picture of the lens.

Phacoemulsification and extracapsular cataract extraction are surgical methods that remove the cataract as well as the front portion of the lens capsule (anterior capsule). The back of the lens capsule (posterior capsule) is left inside the eye to keep the vitreous gel in the back of the eye from oozing forward through the pupil and causing problems. The posterior capsule also supports the IOL and helps keep it in the proper position. These types of surgery are usually done in an outpatient setting and not in a hospital.

Phacoemulsification surgery is the most common type of cataract surgery. It is used more often than standard extracapsular surgery, even though they are similar procedures.

View the slideshow on cataract surgery to see the steps that are done.

During phacoemulsification surgery:

• Two small incisions (one that is 1 mm and the other that is usually 3 mm) are made in the eye where the clear front covering (cornea) meets the white of the eye (sclera).
• A circular opening is created on the lens surface (capsule).
• A small surgical instrument (phaco probe) is inserted into the eye.
• Sound waves (ultrasound) are used to break the cataract into small pieces. The cataract and lens pieces are removed from the eye using suction.
• An intraocular lens implant (IOL) may then be placed inside the lens capsule.
• Usually, the incisions seal themselves without stitches.

During extracapsular cataract extraction:

• An 8 mm to 10 mm incision is made in the eye where the clear front covering of the eye (cornea) meets the white of the eye (sclera).
• Another small incision is made into the front portion of the lens capsule, and the lens is removed, along with any remaining lens material.
• An intraocular lens implant (IOL) may then be placed inside the lens capsule, and the incision is closed.

Anesthesia

Most cataract surgery is now done using a topical anesthetic (eyedrops) or a local anesthetic. Local anesthetic may involve a sedative for relaxation followed by an injection beside, under, or inside the eye to deaden nerves and prevent blinking or eye movement during surgery.

General anesthetic may be necessary for:

• People with extreme anxiety that cannot be controlled with simple sedation or counseling.
• People who are unable to follow instructions during surgery.
• People who are allergic to certain local anesthetics.
• People with other medical conditions that require the use of a general anesthetic.
• Children.

What To Expect After Surgery

Before you leave the outpatient center, you will receive the immediate eye care that is needed after surgery. The surgeon reviews the symptoms of possible complications, eye protection, activities, medicines, required visits (see below), and what to do for emergency care if needed. Portions of the follow-up may be done by another health professional, such as an optometrist or community health nurse.

The eye that was operated on may be bandaged for one night after surgery. You will wear a protective shield over the eye at night for about a week. There is normally no significant pain after surgery.

You most likely will need to see the doctor for checkups within 2 days after surgery, and again after 1 to 4 weeks. Visits should occur sooner and more frequently if any complications occur.

Checkups following cataract surgery include:

• Ophthalmoscopy, to evaluate the inside of the eye.
• Measurement of visual acuity and eye pressure (tonometry).
• A slit lamp exam, to check for lens clarity.

Eyeglasses are usually prescribed 6 weeks after surgery.

Contact your doctor promptly if you notice any signs of complications following cataract surgery, such as:

• Decreasing vision.
• Increasing pain.
• Increasing redness.
• Swelling around the eye.
• Any discharge from the eye.
• Any new floaters, flashes of light, or changes in your field of vision.

Why It Is Done

Cataract surgery may be done when:

• Your work or lifestyle is affected by vision problems caused by the cataract.
• Glare caused by bright lights is a problem.
• You cannot pass a vision test required for a driver's license.
• You have double vision.
• The difference in vision between the two eyes is significant.
• You have another vision-threatening eye disease, such as diabetic retinopathy or macular degeneration.

Reasons not to have surgery (contraindications)

Cataract surgery will not be done if:

• You do not want surgery.
• Glasses or visual aids provide adequate vision.
• Your lifestyle is not affected by the cataract.
• Surgery is not possible because of another medical condition.
• You have vision loss that has been caused by another eye disease. Removal of a cataract may not improve vision loss caused by another eye disease.

Extracapsular surgery using phacoemulsification may not be used if the cataract is too hard to be broken up by sound waves (ultrasound).

How Well It Works

Cataract surgery has an 85% to 92% success rate in adults. In one large study, 95% of people were satisfied with the results of their surgery. The people who were not satisfied were older adults who had other eye problems along with cataracts.¹

People who have surgery for cataracts usually have:

• Improved vision.
• Increased mobility and independence.
• Relief from the fear of going blind.

Extracapsular cataract extraction and phacoemulsification surgery can restore the same amount of vision. But recovery of sight occurs sooner after surgery with phacoemulsification. And it is less likely that you will need glasses for distance vision after phacoemulsification surgery.

Surgery may also improve vision in infants who have cataracts.

Risks

Less than 5% of people have complications from cataract surgery that could threaten their sight or require further surgery. The rate of complications increases in people who have other eye diseases in addition to the cataract.¹

Although the risk is low, surgery for cataracts does involve the risk of partial to total vision loss if the surgery is not successful or if there are complications. Some complications can be treated and vision loss reversed, but others cannot. Potential complications that may occur with cataract surgery include:

• Infection in the eye (endophthalmitis).
• Swelling and fluid in the center of the nerve layer (cystoid macular edema).
• Swelling of the clear covering of the eye (corneal edema).
• Bleeding in the front of the eye (hyphema).
• Bursting (rupture) of the capsule and loss of fluid (vitreous gel) in the eye.
• Detachment of the nerve layer at the back of the eye (retinal detachment).

Complications that may occur some time after surgery include:

• Problems with glare.
• Dislocated intraocular lens.
• Clouding of the portion of the lens covering (capsule) that remains after surgery, often called second membrane or aftercataract (posterior capsular opacification). This is usually not a significant problem and can easily be treated with laser surgery if necessary.
  • Infants have the highest risk (almost 100%) for cloudiness in the back portion of the lens capsule following cataract surgery. If posterior capsule opacification develops after cataract surgery, a laser procedure or a vitrectomy that removes the posterior capsule may be needed. For that reason, most pediatric cataract surgeries remove the central portion of this posterior capsule during the first operation. This may allow better sight and reduce the need for laser surgery.
  • IOLs made of polyacrylic material decrease the chance of posterior capsular opacification more than lenses made of polymethyl methacrylate or silicone.²
• Retinal detachment.
• Glaucoma.
• Astigmatism or strabismus.
• Sagging of the upper eyelid (ptosis).

What To Think About

Phacoemulsification surgery is the most common type of cataract surgery. It is used more often than standard extracapsular surgery, even though they are similar procedures. The major difference is that phacoemulsification uses sound waves (ultrasound) to break the lens into small pieces that can then be removed through a smaller incision. In standard extracapsular surgery, the lens is removed in one piece, which requires a larger incision. The improvement of vision is the same for both procedures, but the healing process is quicker for phacoemulsification.

Removing cataracts using phacoemulsification is preferred over standard extracapsular surgery because:

• The surgery can be done more quickly.
• There is less astigmatism after surgery.
• Recovery of sight after surgery is faster.
• The risk of complications after surgery is less.

People usually need reading glasses (glasses for near vision) after cataract surgery, no matter which type of surgery is performed. But some people may choose to have different lens implants (intraocular lens, or IOL) in their eyes so that one eye can be used for distance vision and the other for near vision (monovision). For more information, see intraocular lens implant (IOL) to replace the natural lens of the eyes.

A type of IOL that allows you to see both distance and near vision is available. But this type of lens is usually not covered by insurance and may be very expensive.

In some children, surgery to remove a cataract that causes significant vision loss may be very important in preventing blindness. The most critical period for the development of sight is from birth to 6 months. The earlier cataracts in children are diagnosed and treated, the more likely it is that their eyesight will be protected.

If a child has cataracts in both eyes that are causing significant vision loss, surgery on the second eye needs to be done within a few weeks. As in adults, both eyes are not operated on during the same surgery to decrease the chance of complications developing in both eyes at the same time.

Surgeons are sometimes hesitant to put intraocular lenses (IOLs) in the eyes of infants younger than 1 year of age because of rapid eyeball growth and lack of information on the effect of IOLs in these children. Most often, an infant has to wear a contact lens to replace the lens that was removed from the eye. If surgery can be delayed until the child is 1 to 2 years old, it may be possible to use an IOL to replace the lens in the eye. Surgery cannot always be delayed, however, because of the risk of amblyopia and permanent vision loss.

Complete the surgery information form (PDF)(What is a PDF document?) to help you prepare for this surgery.

Author:	Jeannette Curtis	Last Updated: October 1, 2007
Medical Review:	Anne C. Poinier, MD - Internal Medicine Christopher J. Rudnisky, MD, FRCSC - Ophthalmology
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