Exotropia

The divergent strabismus (exotrophy, the manifest divergent strabismus) may be permanent or periodic.

[1], [2], [3], [4], [5], [6], [7]

Types of divergent strabismus

Constant divergent strabismus

• congenital
• sensory
• secondary

Periodic divergent strabismus

• basic
• weakness of convergence
• excess of divergence

Congenital divergent strabismus

Congenital divergent strabismus manifests itself at birth in contrast to infantile esotropy.

Symptoms of congenital divergent strabismus

• Normal refraction.
• A large constant angle.
• Can be accompanied by DVD.

Neurological disorders often accompany, in contrast to infantile esotropia.

The treatment is mainly surgical and consists in the bilateral recession of the external rectus muscles, usually in combination with the resection of one or two internal rectus muscles, depending on the size of the angle.

[8], [9], [10], [11], [12]

Other forms of divergent strabismus

Sensory divergent strabismus occurs as a result of a one- or two-sided decline in visual function due to acquired diseases, for example cataracts or other opacities of optical media in children over the age of 5 years or in adults. Treatment is to eliminate the cause of vision loss (if possible), if necessary, use surgical methods.

Secondary divergent strabismus after surgical elimination of esodeviation.

Periodic divergent strabismus

It manifests itself most often at the age of 2 years exophoria, which changes into divergent strabismus under conditions of weakened control, under bright light resulting in reflex closure of the divergent eye, with weakness or illness. Over time, the deviation becomes less controlled.

Clinical Options

• basic type: the deflection angle when fixing a distant object is equal to the deflection angle when fixing a nearby object;
• weakness of convergence in older children and adults. The angle of deflection is greater when fixing a nearby object. Can be associated with acquired myopia;
• the excess of divergence, in which the deflection angle is greater when the far object is fixed. Can be true or simulated.
  • With true type, the angle when fixing a nearby object is always less than the distance.
  • Simulation is accompanied by a high index of AK / A. The angle becomes equal when fixing the near and far objects, with a repeated
    measurement through the lens +3.0 diopters or after a brief one-sided occlusion.

Treatment of divergent strabismus

1. Ocular correction in patients with myopia can in some cases lead to a decrease in deviation, stimulating accommodation and convergence in passing.
2. Orthoptic treatment of diverging strabismus, consisting of occlusion, avoidance of doubling and improvement of fusional convergence, can be effective.
3. Surgical treatment of divergent strabismus is necessary in most patients at the age of about 5 years. Some experts are adherents of the bilateral recession of external rectus muscles; others, on the contrary, recommend bilateral intervention only for patients with excesses of divergence, preferring recession and resection at equal angles of deviation when fixing near and far objects.