ADULT STRABISMUS
Diagnosing and treating misalignment of the eyes
Abnormal alignment of the eyes, or strabismus, is not just a problem seen in children. This is a problem that a number of adults have to deal with daily. It can be a problem that has been present since childhood or a problem that has just begun in adulthood. It can occur at any age. There are numerous causes that include congenital conditions, childhood conditions that have worsened, neurological problems, brain tumors, brain aneurysms, infections, inflammatory causes, thyroid disease, trauma or stroke.
If an adult has strabismus, the first thing that needs to be determined is the cause. If it is a childhood problem that has worsened or never been treated, then a workup is usually not required. If it is new onset, it could be an indicator of a systemic problem that needs to be treated. As a result, the adult must be seen, and it must be determined if further workup is required.
Adults may have a childhood strabismus that was not treated in the past or has worsened with time and become more troublesome. Many adults do not even realize that they can still have treatment for strabismus as an adult. Also, some adults have been told in the past that they were too old for treatment or that surgery will damage their eyes and make them worse. If an adult is symptomatic, they should be evaluated for possible treatment.
For new onset adult strabismus, further workup such as lab work or imaging of the brain or the orbits may be required. Some problems such as exotropia (turning out of the eyes) or superior oblique palsy (causing one eye to be higher) may require no work up and treatment or observation only. Other problems such as a sixth nerve palsy, new onset esotropia, third nerve palsy, or new onset variable deviation may be a sign of an underlying disease process that must be identified.
Numerous disease processes can cause strabismus. A third nerve palsy, which causes the eye to be turned out and down with drooping of the eyelid, can be an indicator of a brain aneurysm that without prompt treatment can lead to death.
A sixth nerve palsy causing crossing of the eye with limitation of abduction of the eye could be a post-viral condition that will improve with time, or it can be an indicator of a brain tumor. New onset strabismus can be an indicator of neurological diseases such as myasthenia gravis or multiple sclerosis that also affect multiple other areas of the body and will need systemic treatment. These are only a few examples of the numerous causes of adult strabismus.
Symptoms from misaligned eyes include obvious ones such as the eyes not lining up correctly or looking normal or double vision. Other symptoms include headaches, difficulty focusing on objects, eye fatigue, tiredness, being off-balanced, difficulty with depth perception, difficulties doing his or her work, inability to drive, neck pain, inability to read, clumsiness. There are some adults that have had a longstanding face turn or head tilt that causes him or her chronic neck pain that can be due to strabismus. Other adults with strabismus will say by the end of the day they are completely worn out from dealing with the problem and just want to lie down.
One of the most troublesome symptoms for the adult is usually diplopia. Diplopia means to see two objects when only one object is actually present. This diplopia can be constant, intermittent or can occur only with certain directions of gaze. It can worsen when tired or under stress. It can be controlled at first, and then with time as the deviation worsens, can no longer be controlled. As the reader can imagine, this can be an extremely disabling problem. It can limit what activities a person can do and has been shown to lead to problems such as depression.
There
are different treatments of adult strabismus. After the cause is
determined, the next information needed is if the deviation is
symptomatic. If a patient has strabismus that is causing no symptoms and
it does not bother the patient how it looks, observation may be all
that is required.
Other types of strabismus will resolve with time with no treatment. This also would require observation. It often will not be overnight and may take three to six months to completely resolve. One such disease process is a sixth nerve palsy caused by a virus, diabetes or high blood pressure. Often these will resolve in about three months. Other deviations caused by a stroke or head trauma can also improve with time. Even though these types can improve with time, it can be frustrating while the adult is waiting for improvement. It can limit his or her abilities at work, at home, or not allow them to drive.
A simple treatment that can work short-term or even be used long-term if needed, is just covering one eye. This will eliminate double vision caused by strabismus. It does not matter which eye is covered and can be left for the patient to decide which eye they can function with better. This will allow the patient to see single, but they still will not have good depth perception, which can still limit a number of their activities.
Other
options for treatment include prism glasses, Botox injection into
extraocular muscles, vision therapy and surgery. Prism glasses can be
done in patients with smaller deviations.
Measurements are made in the clinic, and prism can be ground into the glasses to correct the deviation while the glasses are on. Patients who do not mind wearing glasses or who already wear glasses may do well with this and not require any further treatment. There are also press-on prisms that can be placed on existing glasses. These can correct larger deviations and may be helpful to treat short-term deviations or to treat patients that are not candidates for surgery. The problem many people have with the press-on prisms is that they are noticeable on the glasses and do cause some blurred vision.
Botox
injection into the extraocular muscles is another option. Botox is used
for a number of things at this time, but was originally invented to
treat misaligned eyes. It can be done in the awake patient with just
some topical anesthesia. It begins to work in about 72 hours and wears
off in about three months. It tends to work better for smaller
deviations.
When it wears off, some people remain diplopia free and others may require repeat injections.
Vision therapy which consists of training the brain and eyes to relieve evaluation to
make sure there is not an double vision can be effective in treating
some forms of diplopia. The most common form that it works for is
convergence insufficiency, in which the patient has some tendency of the
eyes to drift outward, causing difficulties with reading and other near
activities.
Lastly,
surgery can be performed to straighten the eyes and relieve the
patient's diplopia. Just like with all the treatments, the patient's
cause of the deviation and symptoms need to be determined. It needs to
be decided if the deviation is stable or still changing, requiring more
time before performing surgery. Surgery is usually done outpatient, and
the patient is able to go home the same day. It consists of loosening,
tightening or moving the muscles around the eyes to the desired position
to straighten the eyes and to correct his or her symptoms. Often, one
surgery can correct the problem, but everyone is at risk of requiring
more than one surgery over their lifetime.
No matter the age, strabismus can be evaluated and treated. Adults with new onset strabismus especially need underlying cause. There are different treatment options available which can make a significant difference in how an adult is able to function in their everyday life.
Dr. John D. Hinrichsen is a pediatric ophthalmologist / strabisumus specialist at Highland Clinic who devotes his practice toward the diagnosis and treatment of eye problems in children. He specializes in the treatment of strabismus, amblyopia, ptosis and nystagmus. He can be reached at (318) 222-8402, at his first-floor offices 1455 East Bert Kouns Industrial Loop, Suite 103, Shreveport, LA. He also sees patients at the Louisiana Eye & Laser Pineville office. To schedule an appointment, call 1-800-437-0153 or visit the website http://www.highlandclinic.com/staff/john-hinrichsen-md.