What is congenital strabismus?
Strabismus can be classified in relation to several factors, depending on the age at which it appears, whether it is congenital or acquired, the disposition of the deviated eye, the frequency at which it appears, or alternation between one eye and the other. However, what it characterises all types of the condition is the need for early treatment. Congenital strabismus is also known as strabismus in newborns. Following our philosophy of preventive medicine, we want to mention the characteristics of this type of deviation, related to the youngest patients who come to our practice.
It is important not to confuse congenital strabismus, which requires early treatment, with other types of strabismus, whose early onset also occurs before 8 months of age. In any case, when parents or school staff suspect a case of strabismus, the child should be taken for an ophthalmological check-up regardless of age.
Congenital strabismus is a kind of ocular deviation, which can also be known as esotropia. You can see that the eye turns towards the nose, or in other words, looks inwards. Normally there is a constant wide-angle deviation of no less than 40 prism dioptres, where the eye will have difficulty moving outwards (known as abduction). In many cases the condition is accompanied by a vertical deviation, such as torticollis and/or nystagmus.
Diagnostic tests
Given the child’s age and lack of ability to cooperate, the Hirschberg test and eye tracking study carried out with an opthalmoscope torch are very useful when making a diagnosis. An electrophysiological study (for evoked visual potentials) is also recommended to identify asymmetrical vision. In each case, organic conditions will need to be ruled out through a dilated fundus examination.
Causes
Although the origin and cause of strabismus is still a matter for debate, experts agree that it can appear during the first 4 months after birth, although it is more evident from 6 months onwards. Patients that have developmental alterations or that were born prematurely may show this type of ocular deviation, and a family history of strabismus could also be a factor.
Treatment
The refraction in the child’s eye must be studied, using cycloplegic or atropine drops, before beginning treatment with optical correction, if necessary. Early surgical intervention is normally advised to correct the deviation. The objectives are both aesthetic and functional, trying to improve binocular vision and help the patient’s vision develop as soon as possible. The treatment will help the child in the future stages of learning that await him or her.
