Cataract Surgery
Cataract Basics
We are all born with a natural lens in each eye. With age, the lens gradually becomes cloudy. This is a normal aging of the lens that occurs in every eye, but at a different rate in each individual. We need to see through the lens, so as it becomes cloudy, vision changes. During cataract surgery, the cloudy lens (cataract) is removed. It is replaced by a man-made clear lens called an intraocular lens implant or IOL. Replacing a cloudy lens with a clear lens improves vision.
Cataracts cause a gradual change in the quality or clarity of the vision. The vision may become blurrier over time, sometimes with glare, halos, or loss of contrast. There may be more difficulty with night driving or reading in low light conditions. Sometimes colors can become harder to distinguish. Not all patients will have all of these complaints. In general though, the symptoms can be described as a decline in vision or more difficulty seeing in certain circumstances. A sudden change in vision is generally not due to a cataract.
A cataract should be removed when its effect on vision is bothersome to the patient.
Some patients are bothered by relatively small declines in the quality of their vision. For example, a patient may have good “eye-chart” vision but still have glare and halos that are making driving at night uncomfortable. This patient may opt to have surgery on a relatively mild cataract. Other patients, however, may feel that in spite of a rather dense cataract, their vision is adequate. They may decide to wait on surgery. Often the changes in vision occur so gradually over many years that a patient may not realize how much their vision is compromised.
There are also times when the cataract has become dense enough that it is hard for the doctor to see through the cataract into the eye to monitor other conditions such as glaucoma, diabetic damage, or macular degeneration. In this case, removing the cataract may be important to address other eye diseases and preserve vision.
Glasses prescription check: to see if glasses update will improve vision. As cataracts progress, they can cause glasses prescription to change, and an updated prescription may provide satisfactory improvement in vision.
Complete eye exam: including the use of dilating eye drops that dilate the pupil and allow examination of all parts of the eye. All of the eye structures need to be checked to determine if there are other eye problems contributing to vision changes. The cataract is examined to assess the degree of clouding present.
Imaging and measurements: completely painless and noninvasive scans of the optic nerve and macula, corneal mapping, and other measurements of the eye including biometry are performed to provide a complete assessment.
The exam and the measurements help determine what type of lens implant and what power of lens implant is appropriate for your eye.
Not every intraocular lens implant (IOL) type is appropriate for every eye. Your surgeon will use the results of your eye exam and the multiple measurements of your eye to determine appropriate options. In addition, patient preference, lifestyle, hobbies, and goals need to be taken into account. Usually this is narrowed down to one to three choices. Your doctor will review with you options which are appropriate for you specifically, and will make a recommendation. The pros and cons of each lens will be discussed. For more information about different types of IOLs, please click here.
No. Once your natural lens is removed, it cannot grow back. You can, however, develop a Posterior Capsule Opacity (PCO).
During cataract surgery, the patient’s clouded natural lens is removed, leaving behind the lens capsule that held the natural lens. The patient’s clouded lens is replaced with a clear, artificial intraocular lens (IOL) which is placed in the original lens capsule. Weeks, months or years after cataract surgery, this capsule can become cloudy or wrinkled, causing blurry vision.
Clouding or wrinkling of the lens capsule occurs when the patient’s own cells migrate across the capsule and gradually form a thicker, hazier layer on the capsule. This is called a posterior capsule opacification (PCO), a “secondary cataract” or “scar tissue.” Since you are looking through this haze created by your own cells, vision can become blurred, often with increased glare. These symptoms usually develop gradually. If the PCO does not compromise vision enough to bother the patient, it does not need to be treated.
PCO’s are very common. Up to one third of patients in the United States who undergo cataract surgery will need a laser procedure to treat the PCO. Certain types of cataracts are more likely to result in a PCO, and your doctor may be able to advise you of this prior to cataract surgery.
Treatment for a PCO is done in the ophthalmologist’s office, with a painless laser and no down-time. It is generally covered by insurance. The procedure is called a Yag laser posterior capsulotomy. The laser is used to make an opening in the cloudy capsule. This allows light to pass through again for clear vision.
The pupil is dilated before the laser. The doctor aims the laser precisely on the hazy lens capsule. Laser is used to create a central opening of the capsule so the patient is no longer looking through the haze. There is no pain. The procedure takes a couple of minutes. You can resume all of your usual activities immediately after the laser.
As with any procedure, there are possible risks and complications with a posterior capsulotomy. Patients may notice a few floaters immediately after the laser. These generally become much less noticeable with time. A temporary rise in eye pressure or inflammation can occur. This is not common and can usually be treated with drops. Most patients are treated with drops for several days after the laser to prevent these issues. Very rarely, a retinal detachment can occur. This occurs in less than 1% of cases, but your retina will be checked before and after the laser procedure as a precaution. Should you have flashing lights, a dramatic increase in floaters, or vision changes, these should be reported immediately.
If the PCO does not cause blurring, glare or streaks of light that are bothersome to the patient, no treatment is needed. Treatment of the PCO is always optional.
Please call our office with any questions.
Planning for Cataract Surgery
You will need to see your primary care doctor within 30 days of surgery to be “medically cleared” to undergo cataract surgery. Even patients with multiple medical problems can generally safely undergo cataract surgery. Intravenous sedation is used (NOT general anesthesia), allowing for a very quick recovery. If you do have underlying medical problems, your doctor will wish to make sure these are reasonably well controlled prior to any elective surgery.
No, this is no longer needed—but you should stay on drops you are already taking such as glaucoma medication, lubricating drops, etc.
Yes, but for most patients this is now very minimal: an antibiotic drop three times per day for one week and an anti-inflammatory drop daily for a month. We use a little pellet of steroid, a Dextenza implant, placed in the tear duct of the lower lid during surgery. This releases steroid over the course of a month and takes the place of frequent steroid drops.
No, blood thinners do not have to be stopped before cataract surgery. For some other types of eye surgery they do need to be stopped.
On the day of surgery, you will be asked to arrive about an hour before the planned surgery. This allows time for paperwork and getting you ready for surgery. We operate primarily out of North Shore Surgery Center in Lincolnwood, but also at Glenbrook Hospital in Glenview. The nurses and the anesthesia provider will review your medical history and administer drops to dilate your pupil. Your doctor will talk to you before surgery to confirm the type of lens implant we plan to use and any other issues specific to your surgery.
No. An anesthesia provider will give you sedating medication through an I.V. This is not general anesthesia, but is a “twilight”, similar to the medication one might receive for a colonoscopy. Depending upon your level of anxiety and your preference, you may be awake or asleep during the procedure. Your anesthesia provider will may sure you are relaxed and comfortable. You will also be given drops to numb the surface of the eye. There is no pain during cataract surgery. If you are awake, you will feel cool water flowing over your eye at times, and perhaps a painless touch around the eye or a very light pressure sensation. You may see colorful lights during the procedure as well – this is normal. The surgery generally takes about 20 minutes, but because the I.V. medication relaxes you, it seems a lot faster to most patients.
Patients may be awake or fall asleep during cataract surgery, depending upon the amount of sedation they receive (see above). Regardless, patients cannot see what is happening. You will not see instruments coming toward you. There is a large microscope above the patient with a bright light. You will see the light (your eye adapts quickly) and lots of colors. Patients comment that the colors are very beautiful!
You will be kept at the surgical center for about a half hour after surgery. The nurses will make sure that you are feeling well. They will review your instructions and give you written instructions to take home. We ask patients to call or page the surgeon if there are ANY questions or concerns, Dr. Wyse carries a pager at all times and Dr. Bamba is available on her cell phone at all times. Because of the I.V. sedation during the procedure, you will need someone to drive you home from surgery. If your friends or family are not available to pick you up, our office can provide you with names of services that can do this. We ask that for at least 24 hours you do not drive or make any important decisions. You will see your surgeon the day after surgery.
We ask you to wear an eye shield while sleeping for one week after surgery. This is so that you do not press on or rub your eye inadvertently while sleeping. You do not need to wear the shield while awake. You may shower and wash your face and hair even on the same day as surgery. Just try not to press on the eye or get a lot of water in the eye. For one week we ask you to avoid things that might promote infection: swimming pools, hot tubs, yard work/gardening, or eye makeup. You should not engage in strenuous activity or lift heavy objects for one week after surgery. Twenty-four hours after surgery you may return to non-strenuous work (a desk job, for example). Most people can also start driving 24 hours after surgery, but this does depend on the specifics of your vision and your eye surgeon must clear you. After one week there are usually no restrictions but this also should be cleared with your surgeon.
Types of Intraocular Lens Implants (IOLs)
Traditionally, after the cataract is removed, the cloudy natural lens is replaced by a single focus (monofocal) intraocular lens implant (IOL). This type of IOL is usually covered by insurance and is considered a basic or standard IOL. A monofocal IOL can be set to be in focus without glasses at distance, intermediate or near. This refers to what is in focus without glasses. Glasses can be worn to provide clear vision at all ranges. Monofocal IOLs do not correct astigmatism, so eyes with significant astigmatism will not be clear at any range without glasses if a monofocal IOL is used. Fortunately there are now many newer types of IOLs that can offer much greater freedom from glasses. These are often called Advanced Technology IOLs.
Advanced Technology IOLs allow patients to be more independent from glasses. These include toric IOLs that correct astigmatism, extended depth of focus IOLs that provide distance and intermediate vision, and multifocal IOLs that provide a range of vision including distance, intermediate, and near vision. Trifocal IOLs are similar to multifocal IOLs. These lenses are not appropriate for all eyes. A full eye exam in combination with measurements of the eye, scanning of the macula and optic nerve, and mapping of the cornea help to determine if the patient is likely to benefit from one or more of these advanced technology options. Just as important, consideration of patient lifestyle, occupation, hobbies, and goals with cataract surgery is taken into account. Your doctor will review which options are appropriate for your eyes. The pros and cons of the different IOLs will be reviewed with you. Your doctor will make a recommendation. The advanced technology IOLs are not fully covered by insurance. It is always appropriate to choose a standard monofocal IOL. Whatever is not corrected in the IOL can be addressed with glasses. Click here to learn more about advanced technology IOLs.
Types of Advanced Technology IOLs
These lens implants correct astigmatism in the patient’s eye. Many people have a cornea that is not perfectly spherical in shape. This asymmetric curvature is called astigmatism. Astigmatism that is not corrected causes blurring at all ranges, near to far. Astigmatism can be corrected in glasses, contact lenses, or in the eye itself with a Monofocal Toric IOL.
When cataract surgery is performed, measurements before surgery will determine how much astigmatism is on the surface of your eye (the cornea). This may not be at all the same as what is in your pre-surgical glasses or contact lenses. If you have significant astigmatism, and you prefer not to be dependent on glasses/contacts, a Monofocal Toric IOL will correct the astigmatism and provide clear vision at distance OR intermediate OR near. The toric IOL is set for a specific range to be clear without glasses. With glasses on, all ranges are in focus.
Monofocal Toric IOLs are not multifocal, so they have to be set for a particular type of vision without glasses (near vision, intermediate vision, or distance vision clear without glasses, but glasses for focal lengths not corrected by the IOL). Every eye is different, so there can be a small amount of astigmatism remaining after a Toric Monofocal IOL is placed, but it is usually minimal.
Limbal Relaxing Incisions (LRIs)
There are times when a Toric Monofocal IOL would overcorrect the amount of astigmatism in the eye, but there is enough astigmatism that if uncorrected, glasses would be needed. In this situation an LRI in combination with a non-toric IOL (monofocal, EDOF, multifocal or trifocal non-torics) may be the best choice. Computerized calculations using the measurements of your eye help determine whether LRIs or a Toric IOL will give the best result. LRIs are microscopic incisions made in the cornea to change its shape and thereby reduce astigmatism. They are not perfect, as every eye heals differently, so there can be a small amount of astigmatism remaining after LRIs. Nonetheless, vision without glasses should be significantly better if astigmatism is treated and residual astigmatism is usually minimal.
(examples: Symfony and Symfony Toric IOLs, Vivity and Vivity Toric IOLs)
Extended depth of focus IOLs (EDOF IOLs), also called Extended Range IOLs, generally provide good distance and intermediate vision without glasses, but patients generally still need glasses for reading. They provide significantly more range than a Monofocal IOL and are available in astigmatism-correcting toric forms. IOLs that provide range of vision generally also cause some glare and halos with night driving. This is less with the EDOF IOLs than seen with Multifocal or Trifocal IOL. These symptoms are usually mild and do not prevent driving at night. There can be a small decrease in contrast sensitivity with IOLs that provide range, but the EDOF IOLs are similar to the standard monofocal IOL in contrast sensitivity.
These lenses are also a good option in patients who are not ideal candidates for a multifocal IOL, but who still desire more range of vision without glasses than a monofocal IOL can provide. In patients with very mild macular issues, such as mild macular aging changes or a mild macular epiretinal membrane, Multifocal IOLs do not work as well. Provided the macular issues are mild, an EDOF IOL is often a very good option.
(examples: Synergy and Synergy Toric IOLs, Panoptix and Panoptix Toric IOLs)
Multifocal and Trifocal IOLs are similar in that they are designed to provide distance, intermediate (computer), and near vision without need for glasses. These IOLs provide the greatest range of vision without glasses. They are also available in astigmatism-correcting toric forms.
Multifocal and Trifocal IOLs are made up of multiple concentric rings of different power (unlike trifocal glasses or progressive glasses). The full benefit of these IOLs are seen when they are placed in both eyes. Lenses that provide range of vision can cause some glare, halos, or a mild decrease in contrast sensitivity, but these are generally mild and overall patient satisfaction with these IOLs is excellent. Patients may still need glasses for some activities (for example: reading small print in dim lighting), but generally function well for most activities without glasses. While we can’t guarantee independence from glasses with any IOL, most of our patients do not need glasses most of the time with multifocal or trifocal IOLs.
Yes. Multifocal and Trifocal IOLs work best when they are implanted in both eyes. This generally provides the best independence from glasses at all distances. Sometimes, however, one eye is not a good candidate for this type of IOL or a standard Monofocal IOL has previously been placed in one eye. When used in only one eye, the patient is more likely to need glasses for some tasks. For example, long periods of reading may be more comfortable with glasses in this case. Nonetheless, the multifocal or trifocal IOL provides much more spectacle independence than a standard monofocal lens does, even if only implanted in one eye. Many patients opt for this choice and thereby lessen their dependence on glasses considerably.
The size, shape, and acrylic material of the advanced technology IOLs are identical to a standard Monofocal lens implant. The placement of this lens, therefore, does not pose an increased risk during the surgical procedure. Toric IOLs of any type need to be oriented properly to correct astigmatism. Rarely a Toric IOL can rotate during the early postoperative period, but not after the first week or so when it “scars” into place. The IOL then needs to be repositioned in a brief procedure. With today’s better Toric IOLs, this is extremely rare and very manageable.
The main risk with IOLs that provide range of vision (EDOFs, Multifocal, and Trifocal IOLs) is glare with night driving after surgery. In general, this complaint is usually mild and tends to be less noticeable with time. Most patients feel that the trade-off of having some glare at night is worth the independence from glasses. In addition, IOLs that provide range can slightly decrease contrast sensitivity. This is generally not noticeable to the patient and overall satisfaction with these IOLs is excellent.
Eyes that are very nearsighted ( -6 or more diopters of nearsightedness) are often longer eyes, front to back. The retina, the inside lining of the eye, is therefore on a little stretch and thinner at its edges, and at slightly increased risk for retinal tears. The risk of a retinal tear is low in nearsighted eyes, but it is a little higher than average. For this reason, whether or not you have cataract surgery, patients with very nearsighted eyes should have an annual dilated exam to check the retina. Symptoms such as new flashes of light or a significant change in floaters should be reported promptly as these symptoms can indicate a retinal problem that may need treatment.
If your measurements indicate that you have a longer than normal eye, as is often the case in very nearsighted eyes, we may recommend a screening by a retina specialist before cataract surgery. The specialist will check your retina looking for any weak areas that might benefit from treatment before surgery to lower the risk of a retinal tear. If treatment of the retina is needed, it is generally done in the office of the retina specialist.
Patients who have been very nearsighted are often used to taking off their glasses or contacts to look at tiny print or small objects held very close to the face. This very near vision is lost with cataract removal since the only way to preserve uncorrected near vision at such close range is to leave the eye very nearsighted. While this can be done, a highly nearsighted prescription is not as functional for most other aspects of life, so it is rarely chosen by patients. It is important for very nearsighted patients to understand that cataract removal does result in loss of the very near uncorrected vision they may be accustomed to. Often we will choose a lens implant to allow you to read without glasses, holding reading material at a more typical range.
Laser Cataract Surgery
Laser cataract surgery uses femtosecond laser to perform part of the cataract surgery. In traditional cataract surgery, ultrasound is used to break up the natural lens of the eye. The pieces of the lens are then aspirated using a tiny device like a vacuum cleaner. One of the key benefits of the laser is that it can break up the lens into tiny pieces before the ultrasound part of the procedure. Ultrasound is then used (as it is in traditional cataract surgery), but much less ultrasound energy is needed to remove the lens as it has already been fragmented. This is gentler on the cornea (the front part of the eye).
The laser can also make incisions in the cornea (LRIs) and precisely open the front of the capsule that contains the cataract. The laser has a built-in imaging device (optical coherence tomography) which is able to obtain real-time 3D images of the eye during surgery. Corneal incisions made by the laser to reduce astigmatism (Limbal Relaxing Incisions) are therefore made with excellent precision.
Laser use during cataract surgery is not fully covered by insurance. For some patients it may offer a significant advantage, depending upon the status of their eye. For others, it may not make a noticeable difference in outcome. There are certain situations in which the laser may be especially helpful (see below). Your doctor will assess this and may or may not suggest Femtosecond laser assisted cataract surgery as an option for you.
Both traditional and laser-assisted cataract surgery can provide excellent results. The laser is always used to reduce astigmatism in the cornea. In some situations, laser-assisted surgery may provide an additional advantages.
For correcting smaller amounts of astigmatism
If there is astigmatism that would be overcorrected with a Toric IOL but is still significant enough to require correction in glasses if left uncorrected, laser assisted reshaping of the cornea is a great option. While larger amounts of astigmatism are more effectively corrected with a Toric IOL, smaller amounts of astigmatism are effectively addressed with Limbal Relaxing Incisions. These incisions are created in the cornea to reshape the cornea and thereby reduce astigmatism. Traditionally performed using hand-held diamond blades, these correcting incisions can also be performed using the laser. While either method of creating limbal relaxing incisions works well for small amounts of astigmatism, the laser may provide more precise astigmatism correction in some eyes.
For very dense cataracts
During surgery, the cataract is broken into tiny pieces which are then removed through a tiny corneal incision. Breaking up a dense cataract requires much more ultrasound energy during traditional cataract surgery. This energy is stressful to the other eye structures, particularly the overlying cornea. This can cause the cornea to swell and become less clear. The laser can break up the lens so that much less ultrasound energy is needed during surgery. This is safer for the cornea if the lens is very dense, and allows for faster visual recovery.
For eyes with certain corneal problems
Some corneas are less healthy and more fragile than others. For these eyes, minimizing the amount of ultrasound energy delivered to the eye is safer. Ultrasound energy can cause the cornea to swell and become less clear. The laser can break up the lens so that much less ultrasound energy is needed during surgery. This is safer for a more fragile cornea and allows for faster visual recovery.
For eyes with conditions that make the lens less stable
The natural lens (cataract) is attached to the inside of the eye with tiny fibers called zonules. These attachments can be weaker and less stable in certain conditions such as pseudoexfoliation, a history of eye trauma, and some types of previous surgery on the eye. When the laser energy is used to break up the lens, there is much less stress placed on the zonules than with traditional ultrasound. This reduces the risk of complications in eyes with unstable lenses.
For eyes with very Narrow Angles
In patients with “narrow angles”, there is very little space between the cornea (the front surface of the eye) and the lens. For this reason, the ultrasound energy used to fragment the lens is more traumatic to the overlying cornea. In an eye with a very narrow angle, it may therefore be beneficial to use the laser to pre-soften the lens so that the amount of ultrasound energy needed is reduced.
While laser assisted cataract surgery has some advantages, especially in certain situations, it is not always recommended. In highly anxious patients, or those whose pupil does not dilate well, or those with a small opening between the upper and lower lid, laser is often not recommended.
- During the laser part of the cataract surgery only a small amount of sedation can be given, so even though there is no pain, anxious patients may not be good candidates for this technology.
- The pupil must dilate adequately for the laser to be used.
- The space between the upper and lower lid has to be large enough for the laser to “dock” on the eye.
- Use of the laser is not fully covered by insurance.
Your doctor will evaluate all of these factors before making a recommendation.
