Strabismus: Causes, Symptoms and Treatment
Strabismus is a misalignment of the eyes in which both eyes do not point in the same direction simultaneously. It can be congenital or acquired.
Things worth knowing about "Strabismus"
Strabismus is a misalignment of the eyes in which both eyes do not point in the same direction simultaneously. It can be congenital or acquired.
What is Strabismus?
Strabismus, commonly referred to as a squint or crossed eyes, is a condition in which the eyes are not properly aligned with each other. While one eye looks straight ahead, the other may turn inward, outward, upward, or downward. Strabismus can affect both children and adults and may be constant or intermittent.
Causes
The causes of strabismus vary depending on the age of the patient and the type of misalignment:
- Genetic factors: Strabismus tends to run in families, increasing the risk in children of affected parents.
- Refractive errors: Uncorrected farsightedness (hyperopia) is a common cause of inward turning (esotropia) in children.
- Muscle imbalance: Weakness or poor coordination of the extraocular muscles that control eye movement.
- Nerve damage: Paralysis of the cranial nerves controlling eye muscles (e.g., due to stroke, brain tumor, or trauma) can lead to strabismus.
- Systemic diseases: Conditions such as diabetes mellitus, multiple sclerosis, or myasthenia gravis may cause strabismus.
- Premature birth: Preterm infants have a higher risk of developing strabismus.
Types of Strabismus
Strabismus is classified based on the direction of eye deviation:
- Esotropia (inward deviation): The affected eye turns toward the nose. This is the most common type in children.
- Exotropia (outward deviation): The affected eye turns away from the nose.
- Hypertropia / Hypotropia (vertical deviation): One eye is higher or lower than the other.
- Manifest strabismus: The misalignment is constantly present.
- Latent strabismus (heterophoria): The misalignment only appears under certain conditions, such as fatigue.
Symptoms
Common signs and symptoms of strabismus include:
- Visibly misaligned eyes
- Double vision (diplopia), especially in adults with acquired strabismus
- Head tilting or turning to compensate for misalignment
- Squinting or closing one eye in bright light
- Impaired depth perception (stereopsis)
- In children: amblyopia (lazy eye) as a secondary complication, when the brain suppresses input from the misaligned eye
Diagnosis
Strabismus is diagnosed by an ophthalmologist or orthoptist using several tests:
- Hirschberg test: Assessment of the corneal light reflex to estimate the angle of deviation.
- Cover-uncover test: The standard test used to detect manifest or latent strabismus.
- Prism cover test: Measures the angle of deviation in prism diopters.
- Fundus examination: Evaluation of the retina and optic nerve.
- Cycloplegic refraction: Measurement of refractive errors after temporarily paralyzing the accommodation to reveal the true refractive state.
Treatment
Treatment depends on the underlying cause, the angle of deviation, and the age of the patient. The primary goals are to preserve or restore vision and to align the eyes as symmetrically as possible.
Glasses or Contact Lenses
When strabismus is caused by a refractive error such as farsightedness, corrective lenses alone can significantly reduce or even eliminate the misalignment.
Occlusion Therapy (Patching)
If amblyopia is present, the stronger eye is patched to force the weaker eye to work harder, thereby improving its visual acuity.
Orthoptic Exercises
Specific eye exercises can improve coordination of the eye muscles, particularly in cases of latent strabismus or convergence insufficiency.
Prism Lenses
Prisms incorporated into spectacle lenses can help reduce double vision and support binocular vision.
Botulinum Toxin Injection
In selected cases, botulinum toxin (Botox) is injected into overactive eye muscles to temporarily weaken them and improve alignment.
Surgical Treatment
For larger angles of deviation or when other therapies are insufficient, strabismus surgery (extraocular muscle surgery) is indicated. The procedure involves shortening, lengthening, or repositioning the muscles around the eye to restore parallel alignment.
Prognosis
When diagnosed and treated early, the prognosis for strabismus is generally good. Children who receive timely treatment have a strong chance of developing normal visual acuity and, in many cases, adequate depth perception. However, untreated strabismus can lead to permanent amblyopia and loss of binocular vision.
References
- American Academy of Ophthalmology - Esotropia and Exotropia Preferred Practice Pattern. AAO, 2017. Available at: https://www.aao.org
- Wright, K. W., Spiegel, P. H. & Thompson, L. S. - Handbook of Pediatric Strabismus and Amblyopia. Springer, New York, 2006.
- World Health Organization (WHO) - Vision Impairment and Blindness. Available at: https://www.who.int/news-room/fact-sheets/detail/blindness-and-visual-impairment
Most purchased products
For your iron balance
Specially formulated for your iron balance with plant-based curry leaf iron, Lactoferrin CLN®, and natural Vitamin C from rose hips.
For your universal protection
As one of the most valuable proteins in the body, lactoferrin is a natural component of the immune system.
For Healthy Oral Flora & Dental Care
Formulated lozenges with Dentalac®, lactic acid bacteria, and Lactoferrin CLN®The latest entries
3 Posts in this encyclopedia categoryPurulent Tonsillitis
Shoulder arm syndrome
Most read entries
3 Posts in this encyclopedia categoryMagnesiumcarbonat
Calorie content
Cologne list
Related search terms: Strabismus