Cataract Surgery Complications

There have been tremendous advancements in cataract surgery in recent years. This has led to improved surgical options and postoperative outcomes for patients. However, as with any surgical procedure, there is always a risk of complications. The good news is that the complication rate in cataract surgery is low. The vast majority of patients who undergo cataract surgery are very happy with their postoperative results.

Despite the high success rate of modern-day cataract surgery, there are some specific complications that can occur. Although they are uncommon, it is helpful to understand what they are and what it might mean for you if one does occur. Keep in mind as you read below, that most of these complications are treated without difficulty, and do not affect the long-term visual outcome. However, there are several that can lead to a permanent loss of vision if they occur.

Infection

Infections can occur with any surgical procedure. In cataract surgery, infection occurs in less than 0.5 percent of patients. If you do develop symptoms of an infection, however, it is important that you contact your doctor immediately so he or she can evaluate you. These symptoms may include pain, decreased vision, light sensitivity, redness, tearing or drainage, or a feeling of pressure. This is one of the few complications that can lead to permanent loss of vision.

Retinal Tears and Detachments

Retinal tears and detachments can occur with any type of surgery inside the eye. Fortunately, tears and detachments associated with cataract surgery are not common. Should you develop one, your cataract surgeon will refer you to a retina sub-specialist, who will care for your retina with laser treatment and/or additional surgery.

The most common symptoms of retinal tears are floaters (tiny black spots floating around in your vision) and flashes of light in your eye. A tear may also be associated with decreased vision if bleeding occurs. The symptoms of a detachment are similar to those associated with tears, but you may also notice a “curtain or shade” coming down over your peripheral vision. Retinal tears and detachments can lead to a permanent loss of vision.

Bleeding

Bleeding can occur inside or around the eye during cataract surgery. With older surgical techniques, the type of bleeding that jeopardizes vision occurred with greater frequency, but advances in technology and technique have led to two main developments in surgery: topical anesthesia and small-incision cataract surgery. These techniques have led to decreased rates of bleeding in and around the eye. Therefore, the amount of bleeding that now occurs during cataract surgery is usually small and inconsequential. It most commonly occurs on the white part of the eye, which does not affect your vision. In very rare cases, you may still have bleeding in or around the eye that can threaten your vision. This usually occurs with ECCE (large-incision surgery) and/or with injection anesthesia behind the eye.

If you are taking aspirin, warfarin (Coumadin), or other anti-coagulant or anti-platelet medication, you should discuss this with your doctor. In most cases, these medications can be continued prior to surgery, but this will depend on your specific surgery. There are some over-the-counter nutraceuticals, such as vitamin E, that act as anti-coagulants, so you should also report all over-the-counter medications and dietary supplements in addition to your prescribed medications.

Increased Eye Pressure

There are several things that can lead to increased eye pressure following cataract surgery. In this case, you may feel this pressure in your eye, which may cause discomfort. This usually resolves naturally within 24 to 48 hours of surgery, but if the pressure is high, your doctor may temporarily prescribe pressure-lowering drops. High pressure is uncommon, and the drops are very effective. If you do not have glaucoma, this is generally not a problem, but if you feel pressure or discomfort, you should let your doctor know so he or she can determine the best course of action.

Wound Leak

Cataracts are still removed through surgical incisions, although these incisions are much smaller than they used to be. On rare occasions, the eye can leak fluid from following cataract surgery. This condition can be easily treated with a bandage contact lens or a stitch, which will usually be removed at your one-week postoperative visit.

Decreased Eye Pressure

Inflammation inside your eye and wound leaks can lead to decreased eye pressure after surgery. In both cases, treatment of the underlying problem will restore normal pressure in the eye.

Swelling of the Cornea

Swelling of the cornea after cataract surgery used to be more common, but due to improvements in technology and surgical techniques, such swelling now is rare in a normal cornea. Typically, this occurs in patients who have either pre-existing corneal diseases, such as Fuchs’ dystrophy, or advanced cataracts.

Astigmatism

Surgically induced astigmatism is common following cataract surgery, but can be managed, and is usually slight with phacoemulsification. In most cases, because it is usually small, it does not cause symptoms. If it is large enough to cause blurry vision, it can be treated after cataract removal with limbal relaxing incisions, laser vision correction, glasses and contact lenses.

Posterior Capsule Disruption

The posterior capsule is a very thin structure. Occasionally, it does not withstand the phacoemulsification power required to remove the cataract. There are some eye diseases that cause the capsule to become more delicate and floppy. In these cases, it will be more susceptible to disruption. If the posterior capsule is disrupted, some of the vitreous may need to be removed. This is a well-known complication of cataract surgery, but it is infrequent. If the capsule ruptures during surgery, your surgeon may place your intraocular lens either in front of the capsular bag or in front of the iris, instead of inside the capsular bag. These are perfectly acceptable locations for your IOL. In the case of posterior capsule disruption, your visual recovery will take a bit longer than usual.

Zonular Disruption

This can occur either from surgical trauma, pre-existing trauma, or in certain ophthalmic conditions that directly lead to loss of zonular structure, such as pseudoexfoliation syndrome or Marfan’s syndrome. This is not always detectable in advance of surgery. If you have a large disruption, your surgeon may choose to place your lens either in front of the capsular bag or in front of the iris. A zonular disruption also increases the possibility that your surgeon will need to remove some of the vitreous in your eye.

Dislocated Lens Fragments

These occur most commonly in the case of a disrupted posterior capsule, but can also occur if there is a zonular disruption. It results from pieces of your cataract falling backward, into the vitreous cavity. If the pieces are small, and come from the cortical part of your cataract, you’ll probably receive extra anti-inflammatory medication, and be required to make a few extra office visits. If the dislocated fragments are nuclear, they will likely need to be removed by a retinal surgeon during an additional procedure. In most cases, you will still get your intraocular lens at the time of your cataract removal, but occasionally, your lens will be placed at a later date. In the case of dislocated lens fragments, your visual recovery will take a bit longer than usual.

Swelling of the Macula

There are two types of macular swelling. The first is called cystoid macular edema (CME). This form of swelling occurs in the very center of the macula. There are certain types of conditions that predispose you to having this swelling, such as diabetes mellitus and uveitis, but it can happen to anyone. If you develop this type of swelling, your surgeon will treat you with medications that are very effective in most cases. Such swelling will cause blurry vision until it is resolved. Early treatment of this condition is preferable; therefore, it is important that you notify your doctor should you notice a change in your vision.

The second form of swelling in the macula is called diabetic macular edema. As the name suggests, this occurs in patients with diabetes mellitus, and is discussed in greater depth in the section on “Cataract Surgery and Other Diseases.” In summary, if you have diabetes, you are at risk of developing swelling in the macula. If you already have diabetic macular edema, it can get worse after surgery; therefore, it is very important to maintain strict blood pressure and blood sugar control before, during and after your surgery.

Retained Lens Material

This is both uncommon and unpredictable. On rare occasions, a small piece of your cataract may migrate either into the drainage system in your eye (known as the angle), or behind the iris. In this case, it will not be visible to your surgeon. These fragments tend to migrate into the anterior chamber after surgery, and often, your eye will simply reabsorb them. If they are causing inflammation or increased eye pressure, your surgeon can take you back to the operating room to remove the retained lens fragment. The surgical time taken for this procedure is usually only several minutes.

Droopy Lid

This can result from the lid speculum placed in your eye while your surgery is performed or from injection anesthesia. It tends to be self-correcting. In the unlikely event that your lid remains droopy after surgery, usually, it can be corrected by an oculoplastic surgeon.

Loss of Vision

This is rare, but it can occur. Patients who lose vision after cataract surgery often have pre-existing eye diseases, such as extreme nearsightedness or glaucoma. Retinal detachments, bleeding, swelling and infections can also lead to loss of vision after surgery. The amount of vision lost will depend on the type of problem and its severity.

Unexpected Refractive Outcome

This occurs when the expected refractive outcome (your estimated glasses prescription) is significantly different from that which is achieved following surgery. This is uncommon, and is easily remedied. It occurs because mathematical prediction formulas are used to determine the appropriate power of the IOL for your eye. These formulas are excellent, and are continually being improved, but they are not perfect and can occasionally lead to under- or over-correction. These unexpected refractive outcomes can be fixed with a change in the IOL, a second IOL (piggyback IOL), glasses, contact lenses, or laser vision correction. You are more likely to experience an unexpected refractive outcome if you have had prior refractive surgery or are very near- or farsighted, since these eyes all have greater unpredictability in their measurements.

Anisometropia

This results from an imbalance in the prescriptions between the two eyes and leads to difficulty using the eyes together. It most commonly occurs in the time frame between cataract surgery in your first and second eyes, and should resolve when your second eye cataract surgery is completed. If it results from an unexpected refractive outcome in your second eye surgery, you may need another procedure to correct it. This problem is usually not treatable with glasses due to the large imbalance between the eyes. It can usually be treated effectively with contact lenses if you are able to wear them, a piggyback IOL or a change in the IOL (an IOL exchange).

Double Vision

This uncommon complication usually results from pre-existing eye mis-alignment or from muscle damage caused by certain types of anesthesia. It can be treated with prism glasses and/or surgery, although it will sometimes resolve on its own as the muscles recover after surgery.

Eye Wall Perforation

This is a rare complication today, but was more common with large incision surgery (ECCE) where injection anesthesia was used more frequently. If it occurs, it can lead to loss of vision.

Risks of Anesthesia

Complications from anesthesia are uncommon in modern-day cataract surgery. They depend on the type of anesthesia you receive and your particular medical history. Your anesthesiologist will discuss these with you once your type of anesthesia has been determined.