Preparing for Cataract Surgery
Cataract surgery is usually done as an outpatient procedure under local anesthesia and takes less than an hour. Preoperative preparations may include:
- A general physical examination for people with medical problems, such as diabetes. Diabetes can cause damage to the blood vessels of the retina, a condition called diabetic retinopathy. If you have diabetes, discuss with your doctor how your blood sugar level may affect the surgery.
- A review of all your medications. In particular, men who take tamsulosin (Flomax), or similar drugs for prostate problems, require special surgical techniques to prevent complications.
- A painless test to measure the length of the eye and determine the type of replacement lens that will be needed after the operation.
- Topical antibiotics (for example, ofloxacin or ciprofloxacin), which may be applied for a day or two before surgery to protect against postoperative infection. Topical non-steroidal anti-inflammatory drugs (NSAIDs) such as ketorolac may also be used before surgery.
All cataract procedures involve removal of the lens (cataract extraction) and replacing it with an artificial lens called intraocular lens (IOL). Cataract extraction is performed by one of three procedures:
- Extracapsular cataract extraction
- Intracapsular cataract extraction -- rarely used today
Anesthesia for Cataract Surgery
There are three methods of providing anesthesia for cataract surgery. Depending on the surgery and the patient, one or more of these techniques may be used:
- Topical anesthesia
- Local anesthesia
- General anesthesia
Topical anesthesia involves topical drops that numb the surface of the eye, and a tiny amount of anesthetic that is injected directly into the eye at the beginning of the actual surgery. Nothing specifically blocks the nerves of the muscles that move the eye. Sedation in the form of an injection through a vein or occasionally as a pill, will help the patient hold the eye still.
In local anesthesia, a sedative injection through a vein is given, followed by injections of anesthetic around the eye to numb the eye and block the nerves to the eye muscles.
General anesthesia is the method of choice for babies, children, and adults who are not able to cooperate.
Phacoemulsification (phaco means lens; emulsification means to liquefy) is the most common cataract removal method in the United States.
The procedure generally involves the following:
- The surgeon makes a small incision at the edge of the cornea.
- The phacoemulsification probe is inserted into the eye. This probe has a hollow vibrating needle attached to a vacuum source. The needle is surrounded by a silicone sleeve.
- Cataract fragments are drawn to the tip of the needle where ultrasonic vibrations break them up so they can be sucked out through the core of the needle.
- To keep the eye inflated during this process, irrigation fluid flows around the needle under the silicone sleeve and back into the eye.
- An artificial intraocular lens is implanted in place of the natural lens.
Most phacoemulsification procedures take about 15 minutes, and the patient is usually out of the operating room in under an hour. There is little discomfort afterward, and complete visual recovery usually occurs within 1 to 5 days.
Phacoemulsification is sometimes combined with glaucoma surgical procedures, for people who have both glaucoma and cataracts.
Extracapsular Cataract Extraction
Extracapsular cataract extraction, the precursor to phacoemulsification, is now generally used only in people who have an extremely hard lens.
The procedure generally involves the following:
- The surgeon makes a larger incision at the edge of the cornea.
- The hard center (nucleus) of the lens is loosened from the rest of the cataract.
- The nucleus is removed in one piece through the larger incision.
- The incision is closed with stitches.
- An irrigation/aspiration probe (similar to a phacoemulsification probe but without the ultrasound) is used to remove the remaining, softer parts (cortex) of the cataract.
- An artificial intraocular lens is implanted in place of the natural lens.
Laser Cataract Surgery
Newer technologies have been developed so that the incisions used in cataract surgery can be made with a femtosecond laser rather than a blade. (The femtosecond laser was originally developed to make the flap in LASIK surgery. It has since been modified to be useful in cataract surgery.) Femtosecond laser also performs a crucial step of cataract surgery called capsulorhexis (making a circular opening of the front membrane of the cataract.) The laser can also soften the lens nucleus so that phacoemulsification will be easier. It still remains to be seen whether laser cataract surgery presents clear advantages over more conventional methods.
Regardless of which technique is used to remove the cataract, a lens implant (IOL) is almost always inserted to correct the optics of the eye, which now has no natural lens.
Replacement Lenses and Glasses
With the clouded lens removed, the eye cannot focus a sharp image on the retina and is functionally blind at all distances. A replacement lens is therefore needed.
Intraocular Lenses (IOLs). An artificial lens, known as an intraocular lens (IOL), is usually inserted immediately after the cataract is extracted. Most IOLs are made out of acrylic, although other materials, such as silicon, are also used.
IOLs are designed to improve specific aspects of vision. In the United States, there are currently 4 choices:
- Monofocal IOLs. These have been used since the 1980's. They can correct either distance or near vision, but not both. Glasses will be needed for the range that is not corrected by the IOL, as well as astigmatism; for example, if the eye can see at distance with the IOL, then glasses will be needed for reading.
- Multifocal IOLs. These have been available since about 2004 and can correct both nearsightedness and farsightedness. However, contrast may be slightly reduced, and some patients may experience mild glare and halos, particularly at night.
- Toric IOLs. These were FDA-approved in 1998. These lenses are designed to correct pre-existing astigmatism, as well as nearsightedness and farsightedness in patients having cataract surgery.
- Trifocal IOLs. The first trifocal IOL has been approved by the FDA in 2019. It can correct near, intermediate, and distance vision and is available in spherical and toric designs.
The patient and the doctor must choose the IOL based on specific visual needs. Many people also need eyeglasses after cataract surgery for reading or to correct astigmatism.
Complications of Cataract Surgery
Cataract surgery is one of the safest of all surgical procedures. Most complications are not serious. They can include:
- Swelling and inflammation. A small amount of inflammation in the area where the cataract surgery took place is common for a day or two after the surgery. Swelling and inflammation can occur elsewhere in the eye; although the risk is about 1%, this complication can be particularly harmful for people with a prior history of uveitis (chronic inflammation in the eye, which can be due to various medical conditions).
- Retinal detachment. In rare cases, the retina at the rear of the eye can become detached from the inside of the eye. If this happens, it needs to be treated promptly.
- Infection. This is very rare (0.2%) but may be serious if it does develop.
- Bleeding inside the eye.
- Posterior capsular opacification. This condition is also known as a secondary cataract that involves clouding of the lens capsule, and is one of the more common complications of cataract surgery. This can be treated with an in office laser procedure.
This is suspected when the eye pressure is elevated. If this occurs after cataract surgery, it is usually one of three forms:
- Rapid onset, usually seen on the first day after surgery, with high pressures; this is a response to one of the agents used during cataract surgery; treatment rapidly lowers the pressure and it is usually completely resolved within a week.
- Elevated pressure that results from the corticosteroid drops used during the post-operative period; this occurs in "steroid responders" and goes away when the drops are stopped.
- A more gradual increase in pressure that occurs over weeks to months; this is more likely to develop into true glaucoma, but is rare.
Glaucoma is a disorder of the optic nerve that is usually marked by increased fluid pressure inside the eye. The increased pressure causes compression of the retina and the optic nerve which can eventually lead to nerve damage. Without treatment, glaucoma can cause partial vision loss, with blindness as a possible eventual outcome.
Factors that Increase Risk for Complications
The risks of complications are greater if you have:
- Other eye diseases.
- Diabetes. Cataract extraction can pose a high risk for the development or worsening of retinopathy, a known eye complication of diabetes.
- 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.) 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 people who were taking the drug at the time of surgery as well as those who had stopped taking the drug for several 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 complications from IFIS.
Preventing Infection and Reducing Swelling
The ophthalmologist may prescribe the following medications after surgery:
- A topical antibiotic for protection against infection.
- Corticosteroid eye drops or ointments to reduce swelling, such as prednisolone. They may pose a risk for increased pressure in the eye.
- Nonsteroidal anti-inflammatory drugs (NSAIDs), such as diclofenac, ketorolac, naproxen, and voltaren. NSAIDs also reduce swelling and do not have the same risks (increased eye pressure) as steroids. Newer NSAIDs approved to treat pain and swelling after cataract surgery include bromfenac (Prolensa, Xibrom) and nepafenac (Ilevro, Nevanac).
- Some ophthalmologists may inject antibiotics and corticosteroids into the eye at the end of the surgery, reducing the number of medications that must be used during the post-operative period.
Returning Home and Follow-up Visits:
- You will probably leave the surgical site within about an hour after surgery. Cataract surgery almost never requires an overnight hospital stay.
- You will need someone to drive you home and stay with you for a few days until your vision improves.
- You will be examined a day or two after surgery and then during the following month. Additional visits occur as necessary.
- For routine cataract surgery, vision has usually recovered by day 5, often sooner. Rarely the vision may remain blurry for up to 6 weeks. If complications occur during surgery, vision recovery may take longer than that.
- When your doctor decides the condition has stabilized, you will receive a final prescription for glasses or contacts.
Protecting the Eye
Postoperative protection of the eye typically involves the following actions:
- The ophthalmologist usually tapes a bandage and a rigid eye shield over the eye at the end of surgery.
- Most surgeons don't require any bandages after the first post-operative visit except to wear just the rigid eye shield at night for the first week.
Other postoperative advice includes:
- Avoid rubbing the eye.
- Use dark glasses whenever in bright sunlight.
- Avoid swimming and exposure to dust and wind.
- Do not bend over unnecessarily for at least one week following surgery.
- Refrain from jumping, running, heavy lifting, and any other strenuous exercise for a few weeks after surgery.
Treatment of Posterior Capsular Opacification (Secondary or "After Cataract")
About 15% of people who have cataract surgery develop a secondary or "after-cataract" called posterior capsular opacification. Posterior capsular opacification is a clouding of the lens capsule that was intentionally left behind, (it is used to hold the IOL in place) when the original cataract was removed. It generally occurs because some cells of the natural lens remain after surgery and can regrow onto the capsule.
The standard treatment for posterior capsular opacification is a type of laser surgery known as a YAG capsulotomy. (Capsulotomy means making an opening in the capsule, and YAG is an abbreviation of yttrium aluminum garnet, the laser most often used for this procedure.) This is an outpatient procedure that involves no incision and can help improve vision and reduce glare.
YAG capsulotomy involves the following:
- The Yag laser has a chinrest and forehead bar for the patient, similar to what is used for a slit lamp exam. Some surgeons use a contact lens to help aim the laser, but if not, nothing will touch the eye.
- There is no pain and the procedure is usually complete within a minute or two.
- After the procedure, the patient may remain in the doctor's office for an hour to make sure that pressure in the eye is not elevated.
- The doctor will usually prescribe anti-inflammatory eyedrops for the person to take at home.
- Most people will find that their vision improves within a day.
- An eye examination for any complications should follow within 2 weeks.
YAG laser capsulotomy is generally a safe procedure. Serious complications are rare, but can include retinal detachment.