Strabismus
Strabismus, also known as crossed eyes, is a disorder in which eyes are misaligned. In adults, strabismus can occur gradually or rapidly. Gradual onset is usually the result of movement of the eye due to loss of muscle tone. Rapid onset, on the other hand, may be an indication of significant head trauma or serious systemic illness.
Diagnosis of strabismus is based primarily on the patient's medical history. Ophthalmologic and neurologic testing should be performed to rule out possible diseases of the eye or brain. In the most common form of strabismus, the eye turns inward toward the nose. In other forms, the eye may turn away from the nose or may turn upward or downward. Generally, the eyes turn in different directions from each other.
BOTOX® (Botulinum Toxin Type A) Purified Neurotoxin Complex was approved as a therapy for strabismus in adults in December 1989. It is thought to work by lengthening the injected muscle while shortening the opposing muscle. The duration of effect is approximately three months. If necessary, the neurotoxin can be reinjected as long as the patient continues to respond and does not have a serious allergic reaction.1
During the administration of BOTOX® for the treatment of strabismus, retrobulbar hemorrhages sufficient to compromise retinal circulation have occurred from needle penetration into the orbit.
BOTOX® treatments may, on occasion, adversely affect muscles next to the injection site causing eyelid drooping or vertical deviation, especially if higher doses of BOTOX® are required as part of the treatment regimen. The treatments may also cause paralysis in one or more muscles outside the eyeball, causing spatial disorientation, double vision, or pastpointing.1
1. BOTOX® Full Prescribing Information.