Periodic esotropia

Introduction to periodic esotropia Cyclic squint (cyclicheterotropia), also known as cyclic squint (cyclicesoropia), clock-mechanism esoteric (clock-mechanismesotropia), refers to the intraocular oblique and orthodontic (or slight internal oblique) alternating and obvious Strabismus. basic knowledge The proportion of illness: 0.005% - 0.008% Susceptible people: no specific population Mode of infection: non-infectious Complications: strabismus strabismus

Cause of periodic esotropia

(1) Causes of the disease

The cause is unknown.

(two) pathogenesis

The etiology and pathogenesis of this disease are still unknown. More than 20 papers at home and abroad have been discussed. At present, there are four kinds of theories.

1. The theory of the biological clock mechanism

Many scholars believe that this disease is related to the normal "biological clock" phenomenon of the body. The biological clock phenomenon is a kind of phenomenon formed by the biological world in the process of evolution and evolution in the billions of years, perceiving the cyclical changes of the external environment and regulating its physiological functions to adapt to the environment. Rhythm phenomenon, like the natural world alternates day and night, the four seasons change, but in recent years, several patients with periodic esotropia observed, and found that the eye position of each case is not the same in the same day, it is considered that the biological clock mechanism can not explain the characteristics of all periodic esotropia .

2. Brain dominance theory

Roper-Hall et al. speculate that periodic esotropia may be associated with changes in brain dominance, as indicated by patients who do not specifically use a hand. These phenomena may indicate that activity on one side of the cerebral hemisphere does not always maintain an advantage over the other side. Still not proved by most scholars.

3. Eye movement control imbalance theory

Reehter has proposed the hypothesis that the hypothalamus or other midbrain nucleus may be defective in patients with periodic esotropia. The following observations have been supported by several clinical observations:

(1) The patient is accompanied by paresthesia and/or lethargy, frequent urination, abnormal EEG, etc.

(2) Most cases have fever, fright, anger, trauma and other incentives before onset.

(3) The periodicity may be changed or disordered due to anger in the course of the disease.

(4) After general anesthesia, the patient's eye position becomes positive.

According to these phenomena, the lesion of the disease is considered to be in the central nervous system that controls eye movement.

4. The mechanism of imbalance in fusion mechanism

According to the rule of continuous esotropia in periodic esotropia, this disease is related to the imbalance of the fusion mechanism. It is believed that most children with this disease have different degrees of hyperopia. Because hyperopia often needs adjustment, it increases the convergence effect accordingly. The eyeball is easy to be deflected inward, so there may be a large implicit oblique before the dominant strabismus, because the external fusion force is controlled, so that the eye position does not skew, and then for some reason, such as mental or psychological Factors such as the external environment and internal diseases have destroyed the balance of the eye position, and the external fusion force has an imbalance of control of the implicit slant, and every other day, intermittent or constant esotropia, the pathogenesis of these three strabismus should be said to be the same. However, the manner and degree of performance are different. The former two can eventually develop into a constant esotropia. The course of the disease is currently not clearly reported. Burian has pointed out that periodic esotropia can be changed after 4 months to several years. Constant esotropia, two cases reported in China, became constant esotropia after 5 and 16 years respectively.

Periodic esotropia prevention

At least 6 months after the onset of the disease, and then strabismus correction. The amount of surgery should be calculated according to the strabismus on the day of strabismus. No matter whether it is operated on strabismus or non-strabismus day, it will not cause overcorrection after surgery, and periodic changes may disappear.

Periodic strabismus complications Complications strabismus strabismus

The variation of strabismus, the periodic variation of the eye position.

Periodic strabismus symptoms common symptoms internal oblique V sign double vision

1. Eye position changes periodically

The general cycle is 48h, that is, the affected eye presents esotropia one day, one day is positive, and a few shows 72h or 96h1 cycle. It is reported that the periodic change disappears in 1 month to 1 year and becomes constant.

2. strabismus

In the presence of strabismus, there is a large angle of strabismus, usually between 30 ° ~ 40 ° (or 40 ° ~ 50 °), and the near and far strabismus are equal or similar, some cases may be associated with mild V sign.

3. Visual function

Visual acuity is normal. There are no binocular monocular and stereoscopic vision in strabismus. In some cases, there may be double vision when strabismus, and two different situations in the positive position. One class is completely orthotopic. At this time, the patient's binocular monocular and stereoscopic vision are completely normal. There is a physiological double vision phenomenon; the other type, the affected eye is not completely orthotopic, but has a small angle of strabismus, but still corresponds to the normal retina.

4. Non-regulatory

The diopter of patients with periodic esotropia is generally around 2.00D. Wearing glasses or not is independent of eye position changes, but fusion can be obtained, and the AC/A ratio can be higher than normal.

5. Eye movement

Eye movement is not limited, but can be manifested as hypertonar rectus.

6. Sudden onset

There are often obvious incentives, such as fever, fright, trauma, etc., starting with periodic regular esotropia, and then gradually becoming constant esotropia.

7. EMG inspection

In some cases, there is an abnormal EMG of the lateral rectus muscle.

8. Other

The changes in eye position in periodic esotropia are basically regular, but there are still three variations.

(1) Variation of the periodicity of the eye position: Temporary disorder may occur due to emotions, etc., and there may be a phenomenon of oblique or continuous 2 days of positive position for 2 consecutive days. In some cases, the eye position period may be shortened to 24 hours or even 12 hours.

(2) Variation of the phase of the positive phase and the oblique phase: the time of the positive phase and the oblique phase may be equal or unequal, and the specific time when the patient's eye position changes alternately is only relatively fixed at a certain stage, and after a period of time, The eye position transformation of the same patient is fixed at another specific time.

(3) Variation of strabismus: The oblique angle of view of patients with periodic esotropia is not very stable, and often varies. The strabismus may be different on each strabismus day, but the difference is generally less than 20, and the non-strabismus day is sometimes positive. Sometimes strabismus for small angles.

Typical periodic esotropia has a specific clinical manifestation, and the diagnosis is not difficult. However, it should be understood in detail when the patient has changed to a constant internal oblique. The variant should be observed for several days before diagnosis.

Periodic strabismus examination

There was no special laboratory examination, and in some cases, the extraocular muscle (outer rectus muscle) had abnormal EMG.

Periodic strabismus diagnosis

Diagnosis can be made according to symptoms and physical examination.

Differential diagnosis

For periodic esotropia with a long onset time, the following diseases should be identified.

1. Internaittent strabismus (internaittent strabismus) Although periodic strabismus also has intermittent nature, but unlike the general intermittent esotropia, the latter has no temporal periodicity, and in the case of fatigue, regulation and fusion damage It does not change from slanting to slanting like intermittent squint.

2. Cyclic oculomotor paralysis The main clinical feature is that the numbness and sputum of the oculomotor nerve appear alternately periodically, and the period is extremely short, usually several seconds to several minutes, and the eye position is deflected outward and downward. With the ptosis, the pupils are scattered, the upper jaw is lifted or retracted, the pupils are reduced, and the eye position is restored.

3. Acute common strabismus (acute comitant esotropia) often sudden onset, first diplopia, and then esotropia, can be expressed as implicit oblique, intermittent internal oblique or constant esotropia, normal horizontal eye movement, complex image spacing in all directions Equal, no periodic regularity.

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