Eye diseases. Strabismus (most important)

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Eye diseases. Strabismus (most important)

Lecture notes, cheat sheets

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21. Strabismus

Strabismus is the deviation of one or both eyes from a common point of fixation, while normal vision is disturbed (the coordinated work of both eyes).

Paralytic strabismus is observed with weakness of the muscular apparatus of the eyeball, which may be due to trauma, tumor, neuroinfections, concomitant strabismus develops in childhood.

Clinically, paralytic strabismus is manifested by the limitation or absence of movements of the squinting eye in the direction of the affected muscle, while there is a feeling of doubling of objects. With a long-term strabismus, vision may be reduced. Concomitant strabismus develops in childhood, while the movements of the eyeballs are preserved in full, and there is no doubling. Deviation of the eye to the nose is referred to as convergent strabismus; when the eye deviates to the temple, strabismus is considered divergent. In addition, there are deviations of the eyeball up and down, as well as a combination of horizontal and vertical deviation of the eyes.

With a constant deviation of one eye, strabismus is considered one-sided, both eyes are bilateral, alternate deviation of one or the other eye is intermittent.

In all patients with strabismus, both the anterior segment of the eye and the fundus of the eye are carefully examined with a dilated pupil.

It is also necessary to examine the visual acuity of the child, first without correction, then with existing glasses. If the vision is below 1,0 in glasses, an attempt is made to correct it.

If even with correction it was not possible to achieve full vision, this may indicate (in the absence of morphological changes in the eye) a steady decrease in vision without visible organic changes as a result of the existing strabismus of dysbinocular amblyopia. The division of amblyopia according to severity:

1) light 0,80,5;

2) average 0,40,3;

3) severe 0,20,05;

4) very severe 0,04 and below.

Then the nature of fixation is determined. This means that non-central fixation is accompanied by very low visual acuity.

In all patients with strabismus, to decide whether they need to wear glasses, examine the clinical refraction by skiascopy or refractometry.

In cases where the correction of ametropia does not completely eliminate the deviation of the eye, the strabismus should be considered partially accommodative.

If the strabismus does not decrease under the influence of correction, therefore, it is of a non-accommodative nature.

The next step in the study is the determination of the angle of strabismus. It is determined by various methods, the simplest of which is the Hirshberg method.

In examining a child with strabismus, it is important to determine the functional state of the oculomotor muscles.

Author: Shilnikov L.V.

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