Dr Alok B S
Kalyan nagar, Bengaluru Feb 9, 2017
It occurs when a person’s eyes are not able to align on the same point at the same time and appear to be misaligned or pointed in different directions. It has other names such as tropia, eye turns, walleyes and wandering eye. It usually occurs in people who have poor eye muscle control or are very farsighted.
It usually develops in infants and young children, most often by age 3. But older children and adults can also develop the condition.
People often believe that a child with strabismus will outgrow the condition. However, this is not true, it may get worse without treatment.
Strabismus is classified by the direction the eye turns:
• Inward turning is called esotropia
• Outward turning is called exotropia
• Upward turning is called hypertropia
• Downward turning is called hypotropia.
Other classifications of strabismus include:
• The frequency with which it occurs, either constant or intermittent
• Whether it always involves the same eye, that is unilateral
• If the turning eye is sometimes the right eye and other times the left eye, that is alternating.
Each eye has six external muscles (called the extraocular muscles) that control eye position and movement. For normal binocular vision, the position, neurological control and functioning of these muscles for both eyes must be coordinated perfectly.
Strabismus occurs when there are neurological or anatomical problems that interfere with the control and function of the extraocular muscles. The problem may originate in the muscles themselves, or in the nerves or vision centers in the brain that control binocular vision.
It may cause severe longsightedness that has been left untreated. Significant head trauma may also cause crossed eyes as it can affect the portion of the brain that controls eye muscles. It also runs in families.
• Eyes appear to be pointed in different directions
• Eyes that do not move together
• Unsymmetrical points of reflection in each eye
• Tilting the head to one side
• Inability to gauge the depth
• Squinting with only one eye
• Eyeglasses or contact lenses
• Medication (eye drops)
• Patching or covering the better-seeing eye
To prevent vision loss, early diagnosis and treatment of crossed eyes are important. Series of tests are there to check the health of eyes that may include:
• corneal light reflex test to check for crossed eyes
• visual acuity test
• cover/uncover test to measure your eye movement and deviation
• retina exam to examine the backs of your eyes.