¿Qué es el estrabismo?

Strabismus is the loss of parallel alignment of the eyes. In this condition, both eyes do not focus on the same point—one eye directs its gaze at the object of focus, while the other deviates in a different direction.

For the eyes to be synchronized in movement and position, equal vision and accommodative ability are required, as well as coordination among the six muscles that control each eye.

Most cases of strabismus occur in children. Childhood strabismus may cause the brain to suppress the image from the deviated eye.

What are the types of strabismus?

  • Esotropia: eyes turn inward.
  • Exotropia: less common; eyes turn outward.
  • Hypertropia: one eye drifts upward.
  • Hypotropia: one eye drifts downward.

In some cases, the same eye always deviates. In others, the deviation alternates between both eyes, known as alternating strabismus.

What are the main symptoms?

  • Misalignment of one eye (loss of parallelism)
  • Reduced visual acuity in one eye compared to the other
  • Abnormal head positions (tilting, turning, torticollis)
  • Double vision (particularly when strabismus begins in adulthood)
  • Poor depth perception, misjudging distances, and loss of binocular vision

No child is too young for an eye exam. Early detection and care of strabismus can prevent permanent problems that may later become resistant to correction. The goal is to prevent amblyopia (“lazy eye”) and ensure proper development of binocular vision.

What are the most common causes?

Strabismus has multiple causes, with no single definitive factor. Family history is an important risk factor. When strabismus appears in adulthood, common causes include tumors, muscle disorders, thyroid conditions, and other medical issues.

What does treatment involve?

Treatment is usually divided into two phases:

Medical Treatment

This varies by case and may include corrective lenses, patching therapy, special prisms, and eye muscle exercises. These treatments aim to improve the function of the weaker eye and strengthen muscular coordination.

Patching therapy is the most important treatment for children with amblyopia. A patch is placed over the stronger (“good”) eye to force use of the weaker (“lazy”) eye, helping its vision improve until both eyes are balanced. In most cases, surgery to realign the eyes is delayed until vision in the amblyopic eye has stabilized.

Surgical Treatment

When medical treatment alone is insufficient and the eyes remain misaligned, surgery may be required to strengthen or weaken specific eye muscles. The ophthalmologist will recommend surgery to improve alignment and vision, but it is usually combined with ongoing medical therapy.

Surgery may involve one or multiple eye muscles and, in some cases, can be replaced with botulinum toxin injections instead of conventional surgery under general anesthesia. The ophthalmologist determines the best approach.

What are the possible complications?

As with any surgical procedure, complications can occur. The most common is the need for a second surgery to achieve the desired results. Less common complications include infections, allergic reactions, or drooping of the upper eyelid.