Cataracts - Treatment

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• The ophthalmologist works under an operating microscope to make a small incision in the cornea of the eye.
• The surgeon then extracts the clouded lens through this incision.
• The capsule is left in place, which adds structural strength to the eye and enhances the healing process. (Less commonly, in intracapsular cataract extraction, the surgeon removes the lens and the entire capsule. There are greater risks with this procedure for swelling and retinal detachment.)
• A replacement lens is then usually inserted.
• A small suture is needed to stitch the incision together.

It takes about 2 to 4 weeks to completely restore vision.

Replacement Lenses and Glasses

With the clouded lens removed, the eye cannot focus a sharp image on the retina. A replacement lens or eyeglass are therefore needed:

Intraocular Lenses (IOL). In about 90% of cataract operations, an artificial lens, known as an intraocular lens (IOLs), is inserted. Until recently, IOLs used to employ a pair of little spring-loaded loops to hold the lens in place. Most IOLs are now foldable, which makes insertion easier. In fact, a prefolded lens is now available that unrolls to fit the eye as body temperature warms it.

Although all the lens materials are presumably chemically inert, there are some reports of specific problems, notably a risk for causing a reaction that leads to the development of secondary cataracts, a condition called posterior capsular opacification. IOLs are usually made of one of the following materials:

• Acrylic: The majority of IOLs are made from acrylic, which allows a controlled unfolding of the lens. Evidence now suggests that this material provides a better visual outcome and fewer complications than other standard IOLs.
• Polymethylmethacrylate (PMMA): Has the longest safety record. A PMMA IOL coated with heparin, a blood thinner, helps protect against the development of a secondary cataract after surgery.
• Silicone: Can be inserted through a smaller incision than other materials. It has the highest rates of secondary cataracts. Newer forms of silicon IOLs may pose a lower risk.
• Crystalens: The FDA approved the Crystalens IOL in November 2003. It is made from a proprietary form of silicone called Biosil. The Crystalens uses "hinges" that allow the lens to move, mimicking the eye's natural ability to focus automatically and seamlessly at all distances. Studies have shown that when used along with standard cataract removal methods, the Crystalens restored a patient's full range of functional vision, from distance to reading vision without total dependence on glasses or contact lenses.
• Tecnis Z9000: The Tecnis foldable IOL was specifically designed to improve functional vision of cataract surgery patients. Tecnis has a patented surface which reduces light scattering (spherical aberration) of the cornea, which can negatively affect vision. In April 2004, The FDA approved new labeling claims for Tecnis, allowing the product's manufacturer to market the lens as a way to improve the driving safety for millions of senior cataract patients. In clinical trials, simulated night driving and visual acuity (i.e., 20/20, 20/40, etc.) results were significantly better in eyes implanted with the Tecnis IOL. In addition, spherical aberrations were significantly less when compared to the traditional lens with the spherical optic.
• AcrySof Natural: Approved in 2003, the yellow-tinted Acrysof Natural IOL was the first foldable lens to filter ultraviolet and blue-light. Eliminating both UV and portions of the high-energy blue light help prevent retinal damage. This lens also conforms to the natural shape of the human lens capsule so it remains centered over the eye.
• AcrySof ReSTOR: The AcrySof ReSTOR IOL is approved in the U.S. for patients with and without presbyopia (farsightedness). The lens enhances vision at near, intermediate, and distant ranges. In clinical trials, 80% of patients who received the lens did not require glasses after cataract surgery. The FDA approved the AcrySof ReSTOR in March 2005.

Other materials are under investigation.

IOLs are designed to improve specific aspects of vision. The choices include:

• Lenses that address a single fixed focal point. Such lenses are suitable either for reading or for distance vision, but not both. If a distance lens is implanted, the surgeon prescribes glasses or contact lenses for reading. If a reading lens is implanted, lenses for seeing distances will be prescribed.
• Lenses that address multifocal points. Multifocal lenses can focus at different points for both reading and distance vision. One study reported that more than 80% of patients with multifocal lenses were able to see 20/40 or better without correction. However, contrast may be reduced and some patients experience glare and halos, particularly at night.
• Lenses are available that will correct astigmatism after cataract surgery.

The patients and the doctor must make these decisions based on specific visual needs.

Contact Lenses or Cataract Glasses. A few patients do not receive a new lens and rely solely on corrective eyeglasses or contact lenses. Such patients may include:

• Patients who are extremely near-sighted.
• Patients with other eye disorders.

In such cases, the patient typically returns to the ophthalmologist for a check up the day after surgery, and three additional check-ups are scheduled over a 2-month period. The ophthalmologist can usually give a final prescription for eyeglasses or contact lenses about three months after surgery.

• Choosing Contact Lenses. Contact lenses allow clear vision but do not magnify, so those who choose contact lenses after surgery may have to wear reading glasses. Contacts can be prescribed either for use only during the day or for extended-wear. Occasionally contact lenses cause problems, such as infection. Those who wear them should call their eye doctor if they have red or watery eyes, pain, or sensitivity to light.
• Cataract Glasses. Until the advent of contact lenses, people who had cataract surgery had no choice but to wear glasses with thick lenses, sometimes called Coke-bottle glasses. These glasses have gotten thinner and lighter in recent years, but they may still be cumbersome. Cataract glasses are different from ordinary glasses and are sometimes difficult to adjust to. Images can seem distorted and may appear suddenly within the peripheral vision. Distances may be hard to judge.

Sometimes a patient has two cataracts and needs to wear glasses between the first and second operation. They are particularly troublesome during this period. The treated eye will see images magnified while the other eye will view them as they actually are, and the brain cannot blend the two images. This is a temporary state that is resolved by the second operation.

Complications of Cataract Surgery

Modern cataract surgery is one of the safest of all surgical procedures. Most complications, even if they occur, are not serious. They can include the following:

• Swelling and inflammation. Risk is about 1%. This complication is particularly harmful for patients with existing uveitis (chronic inflammation in the eye, which can be due to various conditions).
• Glare. Patients may experience glare after surgery from light scattering at the edges of the new lens, particularly with square-edged IOLs, which are typically used with posterior capsular cataracts. In most cases. This is a temporary problem and it resolves after a few weeks. In some cases, it persists and the patient requires a re-operation. Some research suggests that glare can be significant reduced by texturizing the edges of the square lens.
• Materials used in some lenses trigger an immune response in about half of patients. This causes inflammation and tiny deposits of tissue in the eye that lead to secondary cataracts--called posterior capsule opacification. Studies suggest that silicone implants pose the highest rates for inflammation and secondary cataracts, particularly in patients with other eye diseases. Newer silicon IOLs pose less risk. In one study, the lowest rates were with IOLs made of acrylic and heparin-coated PMMA.
• Retinal detachment. In rare cases, the retina at the rear of the eye can become detached. Risk is very low (0.1%), and phacoemulsification poses less of a risk for this than standard surgery.
• Atonia (loss of muscle tone that results in a disturbing glare). (Phacoemulsification poses less of a risk than standard surgery.)
• Glaucoma. This is an eye condition in which the pressure of fluids inside the eye rises dangerously. Risk is very low, but patients should be sure to avoid activities after surgery that increase pressure.

• Infection. This is very rare (0.2%), but is devastating if it does develop.
• Blisters on the cornea. There is a higher risk of rupture with phacoemulsification but the risk is extremely low, particularly for experienced eye surgeons. In 2004, the FDA approved the StabilEyes Capsular Tension Ring (CTR) to help support the eye's capsular bag during cataract surgery, especially in those with weak or broken eye fibers (zonules). A CTR is an open ring made of polymethylmethacrylate (PMMA). The ring goes into the capsular bag itself, stabilizing the eye.
• Bleeding can develop inside the eye. Risk is about 1% for minor bleeding and 1 in 10,000 for severe bleeding.
• An implanted IOL can become damaged or dislocated. Risk is very low.
• The surgery itself can produce vision loss or impairment. The risk for this is 1 in 1,000. (Phacoemulsification poses less of a risk than standard surgery.)
• Macular degeneration. Macular degeneration is a common cause of vision loss in the elderly, in which the retina breaks down. In a 5-year study, people who underwent cataract surgery had twice the risk for progression of age-related macular degeneration. Interestingly, another study reported that cataract surgery significantly helped patients who had existing macular degeneration. More research is needed to refute or confirm this finding.

Click the icon to see an image of macular degeneration.

Phacoemulsification does have some specific complications, although they are rare, particularly with experienced eye surgeons. They include:

• Rupture of the lens capsule.
• Loss of the lens nucleus into the eye fluid. (This will require removal by a specialist and may result in poorer vision.)
• Flying fragments of the lens can damage the cornea or threaten the retina.
• Pre- and postoperative changes in blood pressure, which are generally not a problem, should be observed carefully, since in some cases the changes may be extreme.

In about 30% of cases patients develop secondary cataracts within 1 to 5 years after either procedure, which require different treatment choices.

Preventing Infection and Reducing Swelling. The ophthalmologist may prescribe the following medications:

• A topical antibiotic (neomycin or, more effectively, gentamicin). This drug protects against infection.
• Corticosteroid eyedrops or ointments are often used to reduce swelling. Corticosteroids (commonly called steroids) are potent anti-inflammatory drugs. However, they also pose a risk for pressure in the eye and infection. One study reported less visual sharpness with the use of steroids compared to antibiotics. Some newer steroids such as rimexolone, loteprednol, and fluorometholone may pose a lower risk for abnormal pressure.
• Nonsteroidal anti-inflammatory drugs (NSAIDs), such as diclofenac, ketorolac, naproxen, and voltaren, also reduce swelling and do not pose the same risks as steroids. Newer NSAIDS that have been approved to treat pain and swelling after cataract surgery include bromfenac (Xibrom) and nepafenac (Nevanac).

In one study, applying an ice pack for 2 hours immediately after phacoemulsification improved comfort level and reduced inflammation, even days after the operation. This simple procedure has no adverse effects and patients should discuss it with their surgeons before the operation.

Factors That Increase Risk for Complications. The risks of complications are greater for the following people:

• Patients who have other eye diseases.
• People with diabetes. Intracapsular and extracapsular cataract extraction are known to pose a high risk for the development or worsening of retinopathy, a known eye complication of diabetes. Experts have hoped that phacoemulsification would pose a lower risk, but a 2001 study reported a high percentage of retinopathy progression after this procedure. The amount of experience a surgeon has plays a role in whether or not a patient has this complication.
• People who have taken tamsulosin (Flomax) or other alpha-1 blocker drugs. Tamsulosin is a muscle relaxant prescribed for treatment of several urinary conditions including benign prostatic hyperplasia (BPH). In 2005, a leading ophthalmologic association and the FDA warned that tamsulosin may cause intraoperative floppy iris syndrome (IFIS), a loss of muscle tone in the iris that can cause complications during eye surgery. Problems have been reported both for patients who were taking the drug during surgery as well as those who had stopped taking the drug weeks or months before surgery. Men who have taken tamsulosin or similar drugs should inform their eye surgeon. The surgeon may need to use different techniques to minimize the risk of IFIS. 

Postoperative Care

Returning Home and Follow-up Visits.

• Patients usually leave the surgical site within an hour of surgery. Cataract surgery almost never requires an overnight hospital stay.
• They need to have someone drive them home and stay with them for a few days until their vision is acclimated.
• The patient is usually examined the day after surgery and then during the following month. Additional visits are made as required.
• Vision usually remains blurred for a while but gradually clears, usually over a 2 to 6 week period. (It can take longer.)
• When the doctor decides the condition has stabilized, the patient will receive a final prescription for glasses or contacts.

Protecting the Eye. Postoperative protection of the eye typically involves:

• The ophthalmologist usually tapes a bandage over the eye to protect it during the healing process.
• When changing the bandage, the eye can be cleaned gently using a washcloth dipped in warm water without soap. A new bandage can then be positioned and taped.
• It is very important not to press or rub the eye during this procedure.
• An eye shield may be placed over the bandage at night.

Avoiding Glaucoma. Cataract surgery can cause glaucoma, a condition in which the pressure of fluids inside the eye rises dangerously. It is very important to minimize any activity that increases internal eye pressure. Postoperative cataract patients take the following precautions:

• Minimize vigorous exercise
• Put on shoes while sitting and without lifting up the feet
• Kneel instead of bending over to pick something up
• Avoid lifting
• Limit reading since it requires eye movement. Television is all right.
• Sleep on the back or on the unoperated side

Treatment for Patients with Accompanying Eye Conditions

Cataracts and Glaucoma. For patients with both glaucoma and cataracts, experts recommend:

• In patients with cataracts and poorly controlled glaucoma, a two-step procedure for both eye conditions is needed. The patient first receives a trabeculectomy for glaucoma, followed by cataract surgery. Fluid leakage and the presence of blood in the back chamber of the eye are potential complications of this combined procedure. Phacoemulsification has improved success rates and reduced high complication rates of the double procedure compared with extracapsular cataract extraction. New advances that replace trabeculectomy with nonpenetrating glaucoma surgery may prove to be beneficial.
• In patients who have cataracts plus either closed-angle glaucoma or open angle glaucoma that is stabilized with medication, the cataract may be able to be extracted and medication continued for the glaucoma.
• A major 2002 analysis suggested that the combined approach generally offers better control over eye pressure for patients with both cataracts and glaucoma. The best surgical procedure, however, is still uncertain.

Cataracts and Corneal Disease. Patients who have both cataracts and corneal disease may undergo one of the following:

• Combination Procedure. A single operation that combines three procedures. The combined procedure has been used since the late 1970s and employs extracapsular cataract extraction and intraocular lens insertion with corneal transplantation (called penetrating keratoplasty).
• Sequential Procedure. An operation that uses two procedures sequentially. The sequential option performs the cataract procedures and the corneal transplantation separately.

Recovery of vision is usually much more rapid after the combined procedure than after the sequential procedures. Performing the procedures sequentially may also carry a higher rejection rate of the implant, although a 2003 study found no differences in failure rates between the two approaches after a year.

In any case, many experts recommend that for most patients the sequential procedures may be the better option because it appears to have fewer of the following complications than with the combined procedure:

• Posterior capsule rupture
• Eye fluid loss
• Postoperative refractive errors, which result in abnormal distribution of light patterns

The rate of these errors still depends on the skill of the surgeon and the power of the implanted lens no matter what approach is used.

Secondary Cataracts (Posterior Capsular Opacification) and Their Treatments

About 30% of patients who undergo extracapsular cataract surgery develop a secondary "after-cataract" called posterior capsular opacification. Posterior capsular opacification generally occurs because of the following events:

• After surgery, there are still some natural lens cells left behind that proliferate on the back of the capsule.
• The capsule gradually becomes cloudy and interferes with clear vision the same way the original cataract did.

According to a 2001 study, the probability of developing a secondary cataract was 6% at 1 year, 15% at 2 years, 23% at 3 years, and 38% at 9 years. The risk is lower with phacoemulsification. Secondary cataracts are more likely to occur in younger patients, in those with diabetes, or when cataract surgery is combined vitrectomy (clearance of debris from the fluid in the eye).

Preventing Posterior Capsular Opacification. Studies suggest that acrylic lenses pose the lowest risk for posterior capsular opacification. A number of substances to prevent posterior capsular opacification are under investigation, including tranilast eyedrops, new lens materials, special capsular rings inserted during phacoemulsification, and new coatings on the implanted lens (e.g., thapsigargin, a plant-derived substance). One interesting investigative approach is called bag-in-the-lens implantation, which involves inserting the lens capsule into the IOL, rather than the other way around. In one small study, no patients developed secondary cataracts after this procedure.

Treatment Decisions for Cataracts in the Second Eye. If a person has a cataract in a second eye, the issues for decision making are the same as for the first eye. The time of the procedure in the case of two cataracts is unclear. Doctors have long recommended that surgery on the second eye should be postponed until the first eye has healed and the results known (about a year).

One study has called this recommendation into question. It was conducted in England, where for budgetary reasons, there are long waits for second-eye cataract surgeries. In the study, patients who waited 7 to 12 months for the second-eye surgery reported significant difficulty in reading and performing ordinary tasks during the waiting period. Only 1% of patients who had the second surgery within 6 weeks reported having trouble seeing. In addition, 70% of those who waited experienced problems in depth perception, which can cause difficulty in walking and driving; only 12% who didn't wait reported this problem. Patients with double cataracts should discuss all options with their surgeon.

Treatment for Posterior Capsular Opacification. The standard treatment is laser surgery known as a YAG capsulotomy. (Capsulotomy means cutting into the capsule, and YAG is an abbreviation of yttrium aluminum garnet, the laser most often used for this procedure.)

• This is an outpatient procedure and involves no incision.
• Using the laser beam, the ophthalmologist makes an opening in the clouded capsule to let light through.
• After the procedure the patient should remain in the doctor's office for an hour to be sure that pressure in the eye is not elevated.
• An eye examination for any complications should follow within 2 weeks.

Complications. Laser surgery has become so commonplace that some ophthalmologists use it after cataract surgery to prevent later clouding. However, laser surgery carries its own risks and possible complications, similar to those of cataract surgery itself, and can also lead to poorer vision or blindness. About 1% of laser surgery patients develop a detached retina, which is much higher than the risk from the original cataract surgery.

Click the icon to see an image of a detached retina.

In some people, particularly those with glaucoma or who are severely nearsighted, the pressure in the eye may spike after laser surgery. Certain drugs used for treating glaucoma, such as dorzolamide (Trusopt) or apraclonidine (Iopidine), may helpful for preventing this occurrence. It is strongly recommended, however, that this surgery not be performed to prevent a secondary cataract, but only if the lens capsule clouds up again.

Review Date: 02/22/2006
Reviewed By: Harvey Simon, MD, Associate Professor of Medicine, Harvard Medical School; Physician, Massachusetts General Hospital