This is a problem often associated with amblyopia. Strabismus (cross-eye) consists of a deviation of the eyes away from their normal parallelism. Under normal conditions, ocular alignment is achieved thanks to a balance between the extraocular muscles which surround the eyeball. When this balance is broken, the deviation appears.
Symptoms:
It is common for the eyes of a newborn baby to move independently and, occasionally, to deviate. However, after three or four months, the baby must be able to focus on objects and the eyes must be straight, with no deviation. If you notice that your child's eyes move inwards and outwards, if he or she has difficulty focusing on objects and his/her eyes appear to deviate, you must seek medical attention.
Between 30 and 35% of children with strabismus (squinting) develop a subsequent loss of vision (amblyopia, also known as “lazy eye”). The appearance of strabismus is more common in children under six years of age.
Treatment:
- Prevention: treatment must be started as early as possible. The main objective is a good visual acuity, preventing or correcting the amblyopia or lazy eye, if present (ocular occlusion), and correcting any refractive defects.
- Surgical: in cases of strabismus, the aim of surgery is to restore the alignment of eyes; this is done by weakening or reinforcing the different muscles surrounding the eyeball, as necessary, changing the localisation of the muscle insertion (retro insertion = weakening) or cutting the muscle (resection = reinforcement).
The procedure is carried out under local anaesthetic (peribulbar or retrobulbar).
- Correction of strabismus through Botox® (botulinum toxin): some types of strabismus can be corrected with the injection into one or more extraocular muscles of a substance called botulinum toxin, which produces a relaxation of the muscle. This procedure is performed under topical anaesthesia in adults, and under general anaesthesia in children.
