Ocular recession syndrome is a disorder of horizontal rectus muscle movement characterized by an inward rotation of the eye with ocular recession and simultaneous superior or inferior deviation of the lid fissure with other congenital developmental abnormalities of the eye or the body. It is also known as Duane’s syndrome.
Etiology
Ocular regression syndrome is known to be a congenital oculomotor disorder, but its exact etiology is unknown.
Clinical manifestations
There are three main signs of oculomotor retraction syndrome, namely, impaired external rotation of the affected eye, retraction of the eye during internal rotation, and reduced lid fissure.
1. Visual function
A small number of patients have varying degrees of amblyopia, and most of them have refractive parallax amblyopia, and about 7% have strabismic amblyopia. Only a few patients have diplopia.
2.Eye position skew
The first eye position can be orthotropic, internal or external oblique. It is generally believed that internal obliquity is the most common.
3.Ocular movement abnormalities
The typical ocular regression syndrome is characterized by a marked restriction of external rotation or a complete inability to rotate externally; internal rotation is characterized by varying degrees of rapid upward and/or downward rotation.
4. Lid fissure narrowing and retro-ocularity
Changes in the lid fissure are one of the features of oculocutaneous regression syndrome. Narrowing of the lid fissure may be manifested as changes in the upper and lower lids.
5. Vicarious head position
Almost all patients with medially or externally oblique retrobulbar syndrome have a compensated head position.
Examination
No specific laboratory tests are available.
Depending on the type, EOG and extraocular muscle electromyography (EMG) tracings will show different abnormalities.
Diagnosis
The diagnosis of typical retro-ocular syndrome is not difficult and is usually congenital, but there are also acquired retro-ocular syndromes with the following diagnostic points.
1. Eye position deviation
Observe the first eye position for the presence of internal strabismus, internal occult strabismus, external strabismus and external occult strabismus. Observe whether there is upward and downward deviation during internal rotation.
2.Ocular movement abnormalities
Whether there is any obstacle when turning inward or outward, and how much it is restricted.
3.Ocular regression
Check the prominence of the eye in the first eye position, internal rotation and external rotation. If the difference between internal and external rotation is greater than 2 mm, this sign should be suspected.
4. Lid fissure status
If the difference in the height of the lid fissure between the two eyes is greater than 2 mm, this sign should be considered.
5. In case of monocular disease
The lid fissure should be compared especially with the healthy eye.
6. Stretch test
The anatomical abnormality can be confirmed, if necessary, during surgery.
Treatment
Firstly, refractive error should be corrected and amblyopia should be treated to improve visual acuity and restore monocular function of both eyes in children with this sign. Correction of the ocular deviation in the first eye position should be performed to improve the compensatory head position. In addition, the retraction of the eye and the narrowing of the lid fissure and vertical deviation during internal rotation should be reduced as much as possible.