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All About Cataract Surgery
When should a cataract be surgically removed?
Although cataract removal may be recommended because of the appearance of the lens or specific eye problems, it is important that you understand the options in treating cataracts.
Occasionally, your ophthalmologist may say "your cataract is not ripe enough" or it "is too ripe." These expressions refer to chemical changes the cataract undergoes as it ages. As the condition progresses, the protein of the lens slowly changes, frequently becoming very hard (nuclear) or very soft (cortical). Your ophthalmologist will suggest surgery before the cataract is allowed to age too long (get too ripe), in order to allow greater safety in the surgical procedure.
When a cataract has been diagnosed, consider how your vision affects your quality of life and ability to do the things you ordinarily do. Unless a cataract interferes with work, driving, reading or leisure activities, there is usually no urgent need to remove it, particularly if the condition affects only one eye. There's no harm in waiting if you keep regular appointments with your eye doctor to evaluate how the cataract is progressing and whether or not surgery can be safely postponed. When glasses or magnifiers no longer help, or both eyes develop a cataract, surgery in the eye with the worst acuity is the only option. There is no medicine or other treatment that can dissolve or remove the cataract.
Once the decision to have surgery is made, your ophthalmologist will discuss your chances of achieving a good visual result based on the results of preoperative tests.
The benefits of surgery depend on the health of your retina and optic nerve at the time the procedure is performed. For the majority of people having cataract surgery, vision is restored, perhaps requiring only glasses for distance or reading and sunglasses. If you have other eye conditions, you may still need special optical devices, like magnifiers, after the surgery. However, you may be able to use optical devices with less magnification and find it easier to see without the haze and blur caused by the cataract.
Routine preoperative procedures
A-scan
The A-scan is an ultrasonic probe that measures the length of the eyeball and provides the data to calculate the power of optical correction of the lens implant. Although the use of a multifocal or bifocal type of plastic lens implant is slowly becoming the preferred choice as lenses are developed that are technically superior, most doctors still use a plastic or silicone implant set for distance vision. Within certain limits, it's possible to choose the type of sight you prefer. For example, a very nearsighted person may choose to be less nearsighted (to see at a distance without glasses) as long as the vision in the operated eye still closely matches the nonoperated eye. Otherwise, the inequality of vision will result in visual confusion. This consideration is particularly important if the cataract is only in one eye. Similarly, people who wear glasses to correct farsightedness (hyperopia) may elect to see at a distance without glasses. In this instance, reading glasses will be needed for close work.
Medical evaluation
It is customary to have a medical checkup within the two-week period prior to surgery. If you have high blood pressure, a heart condition, or diabetes, it's important to consult your internist before surgery in case your medication schedule needs to be modified before and/or on the day of surgery. This is particularly true with diabetic medication or with heart conditions requiring blood thinners.
Informed consent
Your ophthalmologist is required to review possible complications with you regardless of their low incidence. Complications often sound frightening but their probability is rare in these days of modern technology and skill.
Optional preoperative tests
Some preoperative tests are recommended only in special situations.
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Condition |
Test |
Purpose |
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Glaucoma |
Visual field |
To determine the presence of visual field defects |
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Macular degeneration, diabetic retinopathy |
Fluorescein angiography |
To determine if the macula or any area of the retina is leaking fluid |
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Corneal dystrophy or for those with previous intracapsular cataract surgery who are being evaluated for a secondary lens implant |
Corneal cell count |
To determine if there are enough corneal cells to withstand a surgical procedure |
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High myopia or previous retinal detachment/injury |
B-scan ultrasonography |
To rule out ocular pathology that can't be seen through a dense cataract |
What surgical procedures are used to remove the cataract?
Performed by an ophthalmologist in a hospital or surgical center, cataract surgery is an elective outpatient procedure. During surgery, the lens is removed and replaced with an artificial one (implant) that performs the same function.
Two types of surgical procedures are commonly performed: extracapsular extraction and phacoemulsification. The extracapsular method has been the standard for over a decade, but with advancing technology in surgical equipment and intraocular lens implants for both methods, phacoemulsification has gradually become the procedure of choice in the majority of cases. The ophthalmologist usually makes the decision at the time of the diagnostic evaluation based on the dilation of the pupil, the state of the lens, the effect of other eye problems such as glaucoma on the mechanics of the eye, and the history of previous eye surgery.
Not all cataracts can be removed by phacoemulsification. If a pupil is too small and doesn't dilate, the lens is too hard, the cataract is too advanced, the eyeball is too deep set or the brow too prominent, then the extracapsular method, which requires stitches, is preferred. Eventually, after about six weeks and once stitches are removed, postoperative vision is comparable with either method.
What does cataract surgery entail?
Extracapsular extraction
1. Incision at the border of the cornea and sclera of about 1/2 inch
2. Opening of the lens capsule to expose nucleus
3. Lens nucleus removed from capsular bag in one piece
4. Cortical material removed by aspiration (suction)
5. Plastic lens implant placed in the capsular bag
6. Eye sutured with seven to nine nylon stitches (Postoperative astigmatism will result from stitches)
7. Removal of some of the stitches after six or more weeks to reduce astigmatism
8. Corrective glasses after stitches are removed, or when astigmatism subsides (usually six to seven weeks after surgery)
Phacoemulsification
1. Small corneal incision of 3/16 inch or rarely a small tunnel incision of 3/16 inch under a conjunctival flap in the sclera or directly in the cornea into the anterior chamber
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Site of small turnnel incision |
Scalpel entering the anterior chamber |
2. Opening of the lens capsule to expose nucleus
3. Lens nucleus fragmented and removed from capsular bag by ultrasonic emulsification and suction
4. Cortical material removed by aspiration (suction)
5. Plastic lens implant placed in the capsular bag
| 6. No stitch or, in some cases, one stitch to close the small incision 7. Little or no astigmatism 8. No stitches to remove. If there's one stitch, it remains there without any ill effect |
One stitch to close small incision |
9. Corrective glasses if needed after the eye stabilizes, usually a few weeks after surgery
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Extracapsular extraction |
Phacoemulsification |
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Pros |
Pros |
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Cons |
Cons |
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What kind of anesthesia can I expect?
In the majority of cases, the doctor performs cataract surgery under local anesthesia instilled directly into the eye and light sedation. However, general anesthesia is appropriate in special situations: a very tense or apprehensive person, a person who cannot cooperate.
Local anesthesia and preparation of the eye is the same regardless of which surgical procedure is used. Your pupil is dilated an hour before surgery with several types of dilating drops applied to the eye at approximately 10-15 minute intervals. Dilation allows a wider exposure to the front surface of the lens. If your pupil does not dilate well, the iris opening may be enlarged at the time of surgery or your ophthalmologist may elect to do extracapsular surgery, which does not require maximum dilation.
An intravenous needle is inserted into an arm vein to infuse saline or sugar solution. This allows the anesthesiologist to give you additional sedation or medication if needed. Since you are not asleep, you will be able to tell the ophthalmologist if you experience any discomfort. The anesthesiologist monitors your breathing rate and blood pressure throughout the surgery.
Most people can go home after a few hours, although it is required that they be accompanied by a family member or friend. In special circumstances, a person may be admitted to the hospital overnight. However, the latter is more the exception than the rule.
What is stitchless surgery?
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Stitchless surgery is a relatively recent development. The wide incision of the extracapsular method, which requires seven to nine stitches, causes postoperative astigmatism for several weeks. To reduce this recovery period and to attain an almost instant visual recovery, a different technique was developed. |
 Eye sutured with seven to nine nylon stitches |
By entering the eye either in the sclera or at the border of the cornea, a narrow opening is made through the sclera or cornea into the eye. This allows a small ultrasonic probe to be easily inserted into the eye to emulsify the cataract. The folded lens implant is then inserted through the tunnel into the capsular bag behind the iris where it unfolds and locks itself into place behind the iris. Saline is injected to raise the eye pressure until the eye seals itself shut. Although the slanted incision is watertight and does not require a stitch, some ophthalmologists place one stitch at the opening of the incision as a precaution.
What about stitches and astigmatism?
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Astigmatism is a normal optical variation (an unequal curvature) in the shape of the cornea, which is correctable with special astigmatic or cylindrical lenses. After phacoemulsification, there is little or no change in astigmatism. However, with extracapsular surgery, there is a temporary increase in astigmatism due to the stitches. Ordinarily, six to eight weeks after surgery, stitches are removed if it's necessary to reduce the astigmatism. Usually, one to three stitches are released under local anesthetic drops. There is no pain associated with this office procedure. |
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Only enough stitches are removed to reduce astigmatism to the lowest possible level. Any remaining nonreactive nylon stitches may be left in the eye without ill effect. Occasionally, a stitch left in place will come to the surface causing irritation. At this point, make an appointment with your ophthalmologist. Removing the stitch is a minor procedure that can be done during a brief office visit.
What is a surgical microscope?
One of the significant advances in instrument development is the surgical microscope that provides a uniform light level and magnifies the details of the eye. Modern surgery could not be done without it. The ophthalmologist looks through a binocular eyepiece with an internal light source. The surgeon controls the suction or phacoemulsification machine with a foot pedal leaving both hands free to hold the surgical instruments. The surgical assistant has a seperate eye piece to observe the procedure and assist the surgeon as directed.
Are lens implants safe?
| The plastic lens implant (intraocular lens) that replaces the cloudy lens is the most important part of cataract surgery. The plastic is nonreactive and cannot cause an allergic reaction. Rejection of an implant is rare and caused only by some extraneous factor unrelated to the lens material itself. Lens implants are permanent and safe unless there is a complication that prevents the safe introduction of a lens at the time of surgery. In those situations, an implant can be introduced as a secondary procedure at a later date. |
Plastic lens implant inserted through the incision at the border of the cornea |
What is a secondary lens implant?
Over two decades ago, when the entire lens, including the capsule, was removed (intracapsular extraction), one had to wear corrective contact lenses or thick "cataract" glasses. Now, many of these people can be evaluated for a special lens implant (secondary lens implant) by their ophthalmologist. Not everyone is a good candidate and only your ophthalmologist can tell you if a secondary implant is right for you. This outpatient surgical procedure is simple, done under minimal local anesthesia, and usually takes about 10 minutes.
Will I still need to wear eyeglasses after surgery?
During the immediate postoperative period, it is customary for most people to continue using their current eyeglass prescription.
A recent development in intraocular lenses is a lens that can focus for distance, intermediate and near range using special optical designs. As the lens is perfected, this "focusing" implant will probably be the lense of choice in most cases. At present, at the end of the healing period, new corrective glasses are generally prescribed. A person who chose to have distance vision without glasses would require only reading glasses. A nearsighted (myopic) person who preferred to remain moderately nearsighted may now read without glasses and continue to wear corrective glasses for distance. Some people choose to wear a bifocal, trifocal or progressive lens as they always did.
Generally, the choice is a matter of personal preference but it may also depend on the optical situation. For example, a myopic or hyperopic (farsighted) person with a cataract in only one eye must continue to be myopic or hyperopic in the operated eye to maintain the balance between the eyes. The power of the intraocular lens is determined by the results of the A-scan test performed on both eyes prior to surgery.
What can I expect after cataract surgery?
Although surgical instruments and procedures have become increasingly sophisticated, resulting in little or no discomfort after the surgery, you must remember that you have had an operation. Depending on the type of surgical procedure performed, recovery takes time, usually a few days to a few weeks. In addition, your ophthalmologist may need to remove stitches.
Your eyes will be examined the day after surgery. A glaucoma test will be done and you receive a prescription for antibiotic drops or a combination of antibiotic and steroid drops to be taken several times a day to prevent infection and an anti-inflammatory drop to reduce inflammation. You may need to wear an eye shield at night to protect your eye and your doctor may suggest that you wear sunglasses out of doors. You will be warned not to take aspirin or products containing aspirin for a short time. If you have high blood pressure, diabetes or glaucoma, your doctor will also tell you when to resume taking your medication for these conditions. In some situations, your doctor may also recommend that you avoid bending (e.g., changing linens on your bed) or lifting (e.g., groceries, vacuum cleaner, laundry basket) for a specified period of time, depending on your condition.
If you are active, tell the doctor before resuming your regular routine:
- Alert your doctor to activities, such as swimming, jogging, yoga, tennis or lifting weights.
- Ask your doctor about restrictions on sexual activity.
- In the days following surgery, taking a shower is fine but shampoo and soap may irritate the operated eye.
- Likewise, in the early stages of wound healing, swimming in chlorinated water -- even with goggles -- can be risky. Once wound healing is complete, wearing goggles in a chlorinated pool provides some protection and can also prevent accidental injury to the eye.
- You can resume driving if your postoperative visual acuity is within the legal limit. Your vision is tested after surgery, so ask your doctor if you may drive. With phacoemulsification, the visual acuity in the operated eye is often excellent within a few days. With extracapsular surgery, the nonoperated eye must have sufficient vision to operate a vehicle.
- If you must take a plane shortly after surgery, discuss it with your doctor. You may be advised to plan your surgery after a vacation or business trip.
- Don't be surprised if you feel tired, have low energy or even feel mildly depressed or let down. Some people may feel "hyper." Either reaction can be related to the anesthesia or can be your way of dealing with the anticipation and stress of the surgery. It is normal to experience mild to moderate apprehension with any type of surgical procedure.
Depending on the visual results, some people may be disappointed or even angry that their vision is not what they thought it would be. This is particularly true when cataract surgery is performed on people with other eye conditions such as glaucoma, diabetic retinopathy, macular degeneration or retinitis pigmentosa, where the visual outcome depends on the severity of the underlying condition.
That's why it is extremely important to discuss visual outcomes with your ophthalmologist prior to the surgery. If you're not happy with the results, discuss your disappointment, anger or frustration with your ophthalmologist during one of your post-surgery follow-up visits. Your ophthalmologist may recommend that you be evaluated for additional optical devices and may suggest the benefits of joining a support group in your locale.
Since each situation is different, it is essential to follow your ophthalmologist's advice and not rely solely on information from other sources.
Can a cataract come back?
A
cataract can't come back, but a "secondary membrane" or thickening of
the elastic lens capsule can form within weeks or months or years surgery.
This causes your vision to become slightly cloudy. It occurs in about
20% of cases and is easily and permanently removed through a procedure
called a YAG capsulotomy, which uses a special cutting laser. The
procedure takes approximately five minutes and is done with anesthetic
drops on an outpatient basis by an ophthalmologist. In this procedure,
a small opening is made in the capsule behind the lens implant so that
light can again reach the retina. The procedure is painless but you
need to have your eye pressure checked the next day. In addition, you
must use eye drops for a few days. Your eyeglass prescription will not
change.
What can go wrong?
Although cataract surgery is technically successful in over 98% of those treated, visual outcome will vary from person to person, particularly for those with multiple eye conditions. As with any surgery, there are risks. That's why doctors do surgery only on one eye at a time.
The Agency for Health Care Policy and Research (AHCPR) lists the following potential complications to be discussed with your ophthalmologist as part of "informed consent."
- drooping eyelid
- infection inside the eye
- swelling or clouding of the cornea
- bleeding
- high eye pressure (postoperative glaucoma)
- nucleus of the lens falling into the vitreous
- retinal detachment
- artificial lens dislocation
- loss of the eye
- blindness
Keep in mind that the precautions observed both prior to and during surgery, as well as postoperative treatments, are all designed to minimize infection, bleeding, glaucoma, malfunction of equipment, or any of the other complications listed.
However, if you experience itching, redness, pain, swelling, or any change in your vision after the surgery, call your ophthalmologist right away. Prompt treatment is important and may prevent additional problems.
By Eleanor E. Faye, MD, FACS; Bruce P. Rosenthal, OD, FAAO; and Carol J. Sussman-Skalka, CSW, MBA