Strabismus is an eye condition when the eyeball has an incorrect position, and the visual axis deviates to the side. The disease is accompanied by unpleasant symptoms: diplopia, dizziness, and a general decrease in eyesight. Therefore, the earlier it is possible to establish a diagnosis and start treatment with surgery, the greater the chances of saving healthy vision.
Strabismus, also called squint, is a deviation of the eyeballs. Each eye has a visual axis that allows them to fixate on one point simultaneously. With strabismus, one axis deviates from the conventional point, which causes the eye to look to the side.
Depending on the degree of severity, latent (heterophoria), compensated, and subcompensated forms are distinguished. Intermittent (esotropia and exotropia) strabismus occurs, most often during stressful situations or when a person is sick. Concomitant strabismus usually occurs in infancy or childhood.
Doctors determine between inward squinting (convergent strabismus or esotropia), in which one eye is directed towards the nose, and outward squinting (divergent strabismus or exotropia) and mixed one (heterotropia). So-called paralytic strabismus leads to paralysis of the eye muscles, usually due to a previous inflammation or injury.
Atypical (rare) forms of strabismus are also possible, associated with rare anomalies (Kearns-Sayre, Brown sheath, monofixation and Duane syndromes).
In childhood, the disease occurs more often at two or three and, on average, in 2% of cases. Approximately 1 in 400 children are born with congenital strabismus.
What are the causes of squint?
Strabismus in adults can be both congenital (due to lack of timely and high-quality treatment) and acquired (as a result of traumatic injury, stroke, paralysis, etc.). Causes of the congenital form of the disease may include:
- Bad heredity (a pathology in one of the relatives) and genetic disorders;
- Adverse effects on the pregnancy (alcohol and some drugs);
- Early childbirth;
- Accumulation of fluid in the brain;
- Cerebral palsy.
In rare cases, strabismus occurs as a result of severe stress. If children under one year have strabismus, the cause is more often myasthenia (neuromuscular disease).
The acquired type is associated with a smaller number of reasons. The most common of them are:
- Craniocerebral injuries of various degrees of severity;
- Paralysis and paresis of eye muscles (ophthalmoplegia);
- Traumatic limitations;
- Detachment of the retina;
- Mechanical strabismus;
- Strabismus due to adhesions;
- Damage to the cranial nerves;
- Some diseases of the nervous and endocrine systems.
The paralytic strabismus can happen suddenly due to a muscle disease, inflammation or a tumour. Circulatory disorders can also be a trigger for squinting. In addition, children with squint often have injuries to their face, brain or eyes during birth.
Symptoms of strabismus
Since this disease is also a cosmetic defect, it can be recognized even visually. Therefore, the objective first symptom of strabismus can be considered the asymmetric position of the iris. In other words, the eye is squinting.
A clear sign of strabismus is a deviation of one eye to the side, up or down, when trying to focus your gaze on any object. Other symptoms often accompany it:
- Burning or trembling eyes;
- Crossed eyes;
- Concentration problems;
- Increased sensitivity to light;
- Tilting the head;
- Reading disability.
The disease is a severe disease that reduces the quality of life. By nature, a person has a three-dimensional vision. With strabismus, this process is absent, and a person receives a flat picture in front of the eyes. As a result, diplopia appears. In addition, the eye excludes the incoming image from the eyeball that squints to eliminate double vision. So a person begins to see only with one eye.
As a result of the disease, children often have torticollis, a curvature of the spine, headaches and rapid fatigue. There are also problems when reading and working with small details.
How is strabismus diagnosed?
Squint should be diagnosed in an ophthalmology office during the initial ophthalmological examination. Then, the specialist prescribes additional assessments to clarify the nature and identify the causes of the disorder. They include some of the following tests:
- Visual acuity test;
- Perimetry - determining the limits of the visual fields and their slightest deviation from the standards;
- Tonometry is a measurement of intraocular pressure;
- Pachymetry determines the corneal thickness and helps to recognize other changes in the cornea;
- Ultrasound of the eye the condition of the eyes in real-time and is the most informative examination test;
- Ophthalmoscopy - is a fundus examination.
An important test is the covering and uncovering test. In the covering test, one eye is covered first. It is then checked whether the eye position of the uncovered eye changes or remains the same. If the eye adjusts again, strabismus may be present. On the other hand, the uncovering test checks whether the uncovered eye tries to compensate for the images through additional movements. In this case, there may be heterophoria (latent squinting).
After all, an ophthalmologist can narrow down the form of strabismus and exclude other diseases. Eye doctors can start appropriate treatment only after an accurate diagnosis.
Conservative treatment methods only occur when the disease is diagnosed early. Most often, you can get rid of strabismus only with the help of surgery. Today, gentle ophthalmological interventions do not violate aesthetics and help patients restore the symmetry of the eyes. Therapeutic methods may include:
- Wearing lenses and glasses for vision correction;
- Photo, laser and magnetic stimulation;
- Special gymnastics for the eyes and exercises for strabismus.
If the squint is advanced or therapeutic measures do not result, surgical intervention must bring the eyes back into a parallel position.
In kids, squint surgery is usually performed under general, and in adults - under local anaesthesia. The most common types of such intervention are:
- Shortening of a muscle due to excision of its fragment;
- Muscle lengthening ( to restore the balance between the eyes);
- Changing the place of the oculomotor muscle fixation to strengthen or, on the contrary, weaken its action.
It helps to eliminate the angle of strabismus, reduce double vision and restore activity.
An innovative technique in strabismus treatment is the application of adjustable sutures. The doctor applies a suture with a reserve and, after the operation, "adjusts" the angle of vision that will be comfortable for the patient.
What can patients expect with squint?
Squinting can often be brought under control with early therapy. However, if not treated in time, strabismus can lead to visual impairment in the long term. As a result, even at school age, it can no longer be reversed.
Therefore, children must be already examined at pre-school age to detect possible squinting of the eyes at an early stage. The sooner the treatment starts, the more chances are to correct the vision and eliminate the cosmetic defect. In kids, the disease can be eliminated almost entirely. They may not even need vision correction with glasses or lenses in the future.
Strabismus surgery has a favourable prognosis, allowing patients to restore their vision in 80-95% of cases.
What is the best treatment for strabismus?
Surgery is the best way to cure strabismus. Surgical correction is possible at any age, including in previously operated patients and complex vertical strabismus.
Can I have strabismus surgery abroad?
Leading specialists take on complex cases and correct problems obtained during operations in other medical centres. Eye clinics abroad might be a good option for strabismus treatment.
How does strabismus surgery work?
Surgical treatment of strabismus consists either in weakening the action of a strong muscle (the one towards which the eye deviates) or, on the contrary, in strengthening a weak opposite muscle.
Can clinics abroad be better for squint surgery?
Delicate and cosmetic methods with an operating microscope are the main strabismus surgery advantages abroad. In addition, using a radio-wave knife for incisions during surgery allows you to cut tissues without contact and reduce blood vessel bleeding due to simultaneous clotting.
Is squint surgery a successful procedure?
Squint surgery is an effective treatment in most cases. In addition to correcting misalignment of the eyes, intervention can also restore binocular vision and widen the field of vision in some cases. The success rate of surgery on strabismus is relatively high - 80-95%.
Where can I get Strabismus treatment?
What are the best clinics for Strabismus treatment?
Who are the best doctors for Strabismus?
Prof. Dr. med. Mathias Maier from University Hospital rechts der Isar Munich
Dr. med. Detlef Deiermann from Academic Hospital Bundeswehr Berlin
Prof. Dr. med. Thomas Kohnen from University Hospital Frankfurt am Main of Goethe-University
Prof. Dr. med. Siegfried Priglinger from University Hospital Ludwig-Maximilians Munich
PD. Dr. med. Ira Seibel from Helios Hospital Berlin-Buch