Strabismus (Misaligned Eyes)

Misalignment of the eyes (strabismus) is a condition in which both eyes do not point in the same direction. It occurs in approximately 4 percent of the population in the United States. Although this eye disorder may run in families, it may also be related to other conditions such as cerebral palsy, Down syndrome, hydrocephalus or brain tumours.

When the eyes turn in, this is called esotropia. Types of esotropia include infantile esotropia, accommodative esotropia (related to farsightedness) and sixth nerve palsy. Exotropia is when the eyes turn outward. There are also vertical misalignments of the eyes that can occur.

While misalignment can occur in babies and young children, older children and adults can also develop the condition. Fortunately, with proper treatment, the eye alignment can be improved in most cases. 

Symptoms of Strabismus:

• Decreased vision
• Double vision*
• Impaired depth perception
• Difficulty reading
• Headaches

*If you or your child suddenly experience double vision, seek immediate medical attention, as it may indicate a more serious neurologic disorder.

Tests

A complete eye exam is the first step to developing an effective treatment plan. During this exam, the ophthalmologist may use several testing methods to determine the severity of the condition and the best course of treatment. 

These include:

Visual Acuity – The patient reads letters from an eye chart to evaluate the vision. Very young children may be tested by looking at pictures instead of letters.

Motility Exam – A doctor examines the eyes to see if they are properly aligned and if there is any muscle dysfunction.

Refraction – As part of the exam, the doctor places a series of corrective lenses in front of the eyes to find the correct lens power the patient needs to compensate for a refractive error (near-sightedness, farsightedness or astigmatism).

Treatments

Eyeglasses or Contact Lenses – Special eyeglasses or contact lenses help straighten the eyes in some patients.

Prism Lenses – If needed, the patient can be fitted with special prescription eyeglasses that have a prism power in them.

Patching – Patching the normal eye a few hours each day forces the weaker eye to work harder. Over time, the vision in the weak eye becomes stronger, which may improve eye alignment.

Medications – Young children who cannot tolerate an eye patch may benefit from atropine eye drops. These drops temporarily blur vision in the normal eye, making the weaker eye work harder. This strengthens the vision in the affected eye.

Eye Muscle Surgery – If conservative treatments are not sufficient, an eye surgeon operates to weaken or strengthen the eye muscles and realign the eyes. Surgery is most successful when performed early, to establish binocularity – the ability of both eyes to focus on an object to create a single image.