Epidemiology: Esotropia is one of the most commonly encountered forms of strabismus.
Symptoms and diagnostic considerations: There are three forms of esotropia:
1. Congenital or infantile esotropia: Strabismus is present at birth or develops within the first six months of life.
This form is characterized by a large alternating angle of deviation (Fig. 17.4a and b), lack of binocular vision, latent nystagmus (involuntary oscillation of the eyeballs that only occurs or becomes more pronounced when one eye is covered), intermittent inclination of the head in the direction of the leading eye, and additional hypertropia (primary oblique muscle dysfunction and dissociated vertical deviation).
— Alternating esotropia.
— Alternating esotropia.
Another motility disorder that always occurs in infantile strabismus syndrome is the A or V pattern deviation. This is the result of anomalous central control, i.e., anomalies in the pattern of nerve supply to the rectus and oblique muscles.
❖ "A pattern deviation" refers to an inward angle of deviation that increases in upgaze and decreases in downgaze.
❖ "V pattern deviation" refers to an inward angle of deviation that decreases in upgaze and increases in downgaze.
2. Acquired strabismus: Two forms are distinguished:
❖ 1. Strabismus begins at the age of incomplete sensory development, i.e., between the ages of one and three. Usually the disorder manifests itself at the age of two and leads to sensory adaptation syndromes in the form of unilateral strabismus. Amblyopia is usually already present, and correspondence is primarily anomalous.
❖ 2. Strabismus manifests itself between the ages of three and seven. This form of acute late strabismus with normal sensory development is encountered far less frequently than other forms. As binocular vision is already well developed, affected children cannot immediately suppress the visual images of the deviating eye. As a result, they suffer from sudden double vision at the onset of strabismus, which they attempt to suppress by closing one eye. Immediate treatment is indicated to preserve binocular vision. This consists of the following steps:
- Objective examination of refraction with the pupils dilated with atropine or cyclopentolate is performed to determine whether a refractive error is present. Clinical experience has shown that moderate and severe hyperopia will be detected more frequently than in the congenital form.
- The angle of deviation is precisely determined and corrected with prism eyeglasses.
- Surgery is indicated if eyeglass correction fails to improve the angle of deviation within a few weeks or the eyes are emmetropic.
H Binocular vision is well developed in late strabismus with normal sensory development. Surgery within three to six months will allow the patient to maintain or regain stereoscopic vision.
3. Microstrabismus: This is defined as unilateral esotropia with a minimal cosmetic effect, i.e., an angle of deviation of 5 degrees or less. As a result, microstrabismus is often diagnosed too late, i.e., only at the age of four to six. By that time the resulting amblyopia in the deviating eye may be severe. Another sequela of microstrabismus is anomalous retinal correspondence. Binocular vision is partially preserved despite anomalous retinal correspondence and amblyopia. However, it can no longer be improved by treatment. For this reason, treatment is limited to occlusion therapy to correct the amblyopia.
Was this article helpful?