Although many adults are affected by this condition, strabismus — which presents as misaligned or "crossed eyes," — is most commonly seen in children.
At Scheie Eye Institute, the doctors of the Neuro-Ophthalmology Service are experts at treating adult strabismus. The pediatric ophthalmologists at Children's Hospital of Philadelphia combine the expertise of ophthalmology, neurology and pediatric ophthalmology to treat strabismus in children. To refer a child for treatment, call (215) 590-2791 for an appointment with Pediatric Ophthalmology.
- What is Strabismus?
- Causes of Strabismus
- Symptoms of Strabismus
- Treatment of Strabismus
- Non-surgical Treatment of Strabismus
- Surgical Treatment of Strabismus
What is Strabismus?
Strabismus is the medical term for misaligned eyes - a condition that occurs in 3-5% of the population. The eyes may turn inward (crossed aka esotropia), outward (splayed aka exotropia), or be vertically misaligned (hypertropia). In some cases, each eye may alternate between looking straight ahead and turning. As a result, the eyes do not work together. Each sees a different image, rather than the normal single fused image.
Strabismus can occur at anytime - infancy, early childhood, or adulthood. In some adults it may be a worsening of a childhood misalignment and may result in double vision. Children are rarely afflicted with strabismus-related double vision because their brains are able to process the image from one eye while suppressing the vision in the other.
Some individuals use the term "lazy eye" to refer to strabismus, but this latter term is also used to refer to amblyopia (a condition in which one eye does not develop vision normally).
Causes of Strabismus
The most common causes of strabismus in adults:
- Childhood history of strabismus (with or without previous surgery)
- Orbital disease such as thyroid eye disease
- Previous stroke or previous neurosurgical procedure
- Head trauma
- Diseases that affect the nerves, such as multiple sclerosis
- Poor vision in one eye
Symptoms of Strabismus
The main symptom of strabismus is a misaligned or turned eye, although significant misalignment may be present without a visible difference in the position of the two eyes.
Depending upon their age at the onset of the disease, people with strabismus may or may not experience double vision (diplopia), but adults frequently experience this symptom.
Children below the ages of 6 or 7 usually do not develop double vision although they may sometimes appear to be squinting. A child's brain has the unique ability to suppress the image in one eye; essentially viewing the world through one eye at any given time. In many cases they begin to favor one eye, in these instances the other unused eye can develop a condition known as strabismic amblyopia.
The ability to suppress the vision in one eye is maintained for life. However, people who suppress the vision in one eye do not develop true depth perception (stereopis). Most people function well in life without depth perception because they learn to use other visual cues to compensate for their lack of stereopsis.
Patients with strabismus may experience symptoms that seem vague including trouble focusing, eyestrain, images jumping, difficulty tracking on a page, or loss of peripheral vision.
Treatment of Strabismus
The primary goal is to align the eyes and restore binocular vision. Treatment depends on the type of strabismus, so only after a complete eye examination can an appropriate optical, medical or surgical therapy be determined.
Non-surgical Treatment of Strabismus
The use of standard eyeglasses can correct some forms of strabismus. Spectacles with prisms -- eyeglass lenses that shift images from one eye to the other -- may also be useful in certain types of strabismus, particularly with adults.
It is important to note that some eye care professionals consider the use of prisms to treat strabismus to be controversial. However, prisms in glasses have rarely resulted in a worsening of alignment over time.
Eye exercises have been used to treat a form of strabismus known as convergence insufficiency, but otherwise do not appear to be helpful in treating other forms of the disease.
There are no medications available to treat most forms of strabismus.
Surgical Treatment of Strabismus
If glasses do not correct the misalignment, surgery can be a successful option. Surgery frequently involves both eyes, which can be straightened surgically by shortening or lengthening the muscles that control eye movement.
Your surgeon may choose to use an adjustable suture. In this procedure, the operation is done to place one or more muscles on a pulley. The pulleys are then adjusted the next day with the patient awake thereby increasing the likelihood of successful alignment of the eyes. There is only minimal discomfort involved with this adjustment procedure.
People recover quickly from this procedure and are able to return to normal activities within a few days. In a few instances, additional surgery may be necessary to keep the eyes aligned. Strabismus surgery is usually a safe and effective treatment.
Strabismus surgery has few serious complications. In a small number of patients the eyes remained misaligned after surgery. Rare complications include bleeding, perforation of the eye, infection, retinal detachment, and diplopia.
Need an appointment? Request one online 24 hours/day, 7 days/week or call 800-789-PENN (7366) to speak to a referral counselor.