Strabismus occurs when the two eyes do not line up with each other. Usually, one eye appears to be wandering, and the other eye appears straight. You may have heard this referred to as “crossed eyes” or “wall eyes” or “lazy eyes.” An adult patient with misaligned eyes may have had strabismus since childhood that was never successfully treated, or they may have had an illness or injury later in life that lead to strabismus.
Each of your two eyes sees a slightly different picture of the world. If you have binocular vision, it means your brain can take the two pictures from the two eyes and put them together in a single three-dimensional perception of the world around you. This is a complex skill that is quickly lost in childhood if the two eyes do not line up (but a child’s brain is resilient and has ways to overcome the absence of binocular vision).
When strabismus begins in childhood, the brain learns to ignore the image from one eye just to avoid double vision, a phenomenon called suppression. On the other hand, when strabismus begins in adulthood, the brain is unable to just ignore one eye; in this case, double vision can emerge. Patients with double vision might try closing or patching one eye, tilting their head, wearing prism glasses, or covering one lens of their eyeglasses with tape or nail polish, all in an attempt to get rid of the double image.
Amblyopia is a loss of vision in one that develops in childhood when the brain decides to ignore a misaligned eye to avoid double vision (suppression). When amblyopia develops, the brain never learns to see clearly out of the eye that is being suppressed. Once amblyopia occurs, it must be treated right away, or the lost vision will not be recovered. Amblyopia cannot be treated in adults, but if the eyes are misaligned, they can still be straightened, even if amblyopia is present.
As an adult with strabismus, you may have been told in the past that nothing can be done. This is simply not true! In most cases, eye muscle surgery for strabismus is a successful, safe and effective treatment for adults of all ages.
Having several surgeries does not necessarily mean your eye position cannot be corrected. Some doctors may not have a lot of education or experience treating complex eye muscle conditions. The doctors specializing in adult strabismus at Thomas Eye Group treat complex strabismus on a daily basis. Using specialized techniques, they can help patients who might not be able to be treated elsewhere. There are a few patients who truly cannot be “fixed,” but the only way to be sure is to visit us for a consultation about your particular eye muscle condition.
Many adults with strabismus ask this question because they are no longer children but have been referred to as “children’s eye doctor.” The answer is that misaligned eyes are common in children, and less common in adults, and ophthalmologists who care for children tend to have more training and expertise in treating eye muscle problems. At Thomas Eye Group, our pediatric ophthalmologists are specially trained to perform the delicate eye muscle surgery required to align the eyes properly in patients of all ages. If you do require surgery, it can be performed at our adult-friendly surgical facilities where you will receive appropriate operative and postoperative care.
Many people believe that their misaligned eyes are a cosmetic issue and that they are being vain for even thinking about having them corrected. Family members and friends should understand that there is only one normal position for the eyes, and that is to have both eyes looking in the same direction at once. Anything else is a medical disorder that can and should be treated. As previously stated, some adults develop terrible double vision, and others may have difficulty driving because of decreased depth perception and limited side vision. There is no doubt that the treatment of strabismus is considered a reconstructive, not cosmetic, medical procedure.
Most insurance companies do cover eye muscle surgery because it is a medical condition and causes functional disability. Some programs require preauthorization and others may initially decline if they are not educated about the reasons for surgery. In this case, we contact the insurance company directly and more often than not we are able to come to an understanding. It is rare that an insurance company will not pay for strabismus surgery.
In both children and adults, the surgery is usually performed under anesthesia. Once the patient is asleep, an incision is made over the white part of the eye, and the muscle of interest is separated from the eye. The doctor then reattaches it to the eye with tiny sutures, but in a different (more preferable) position. Despite what you may have been told, there is no need to remove the entire eye to perform strabismus surgery! When a muscle is moved to a new position, the result is either the muscle will not pull as hard on the eye as before, or it will pull a little harder, whichever is desired to straighten the eye position. This new positioning of the eye muscles changes the angle of the eye.
An adjustable suture is a kind of slipknot that holds an eye muscle in place; in eye muscle surgery, these sutures allow the ophthalmologist to readjust the position of the eye after that patient has had time to wake up from anesthesia. Once a very popular technique, most eye muscle surgeons have found limited usage for adjustable sutures and limit them to a select few patients.
Eye muscle surgery is not always perfect. Formulas are used to calculate the number of millimeters a muscle is moved to correct a given quantity of strabismus, but in some cases, there may be more or less correction than desired. The general rule of thumb is that the likelihood of needing only one surgery in the course of a lifetime is about 70%. The primary message is that some people will need more than one surgery to achieve their goals. The likelihood of success after two surgeries is 92% and after three surgeries are 99%. Patients rarely go on to have a fourth or fifth surgery.
It is common for the eye position to fluctuate temporarily in the first two months following surgery; therefore, we wait three months after surgery to determine if the final result is good.
Patients typically worry the most about complications from anesthesia, but anesthesiology techniques have advanced a great deal over the past 20 years. As a result, the risk of a healthy patient being injured from anesthesia is three to five times less than the risk of being injured during a car trip. A very rare complication from eye muscle surgery is an injury to vision or the eye itself. This is extremely rare, and eye muscle surgery is considered one of the safest forms of eye surgery.
Despite our best efforts and careful measurements, some patients end up needing additional surgery, particularly if there is persistent double vision. In some rare cases, straightening the eyes may cause the eyelids to appear imbalanced, which may need to be addressed surgically. Individuals who have had multiple eye muscle surgeries can, on rare occasions, have persistent redness in the area of their surgery.
There will be minor discomfort and blurry vision in the operated eye for 24 to 48 hours after the surgery, but most patients find they function around the home easily in the immediate postoperative period. There are sutures in place which may feel irritating as they gradually dissolve, and the white of the eye will be red, gradually returning to normal over about 2 months’ time.
It is true that a minority of patients will experience drifting of their eyes years after surgery, perhaps not for many years afterward. For most patients, this does not happen. If the drifting does return, it is usually possible to repeat the surgery and restore the benefits of straight eyes. The goal is to live the majority of your life with straight eyes, and for some people that means a second surgery.
In a few patients, Botox® (botulinum toxin) can restore normal binocular alignment. The advantage of Botox® is that it avoids traditional surgery, but it is appropriate only for a small minority of patients.