What is it?
There are seven extraocular muscles: four straight muscles and two oblique muscles, and the upper eyelid levator. They are responsible for moving the eyeballs toward the object of attention in the visual field, and the images perceived by each eye to merge into one in the cerebral visual cortex.
Complicated neuronal, brain circuitry and the oculomotor nerve (cranial nerves III, IV and VI) control, direct and coordinate the actions of the eye muscles.
The term paralysis defines the decreased strength of a muscle, which produces a reduced rotational movement of the eyeball in the direction corresponding to the paralyzed muscle. The deficit is called partial and total deficit paresis, paralysis. They may appear isolated or associated with each other.
There are a number of signs and symptoms that are common to all paralysis: diplopia (double vision). It is the most common. It occurs because the anomalous position of the eyeball affected by the paralysis makes the image of the object being viewed not fall into the same point in both retinal retinas. There may be torticollis (abnormal head position adopted by the patient to compensate diplopia) and ocular deviation.
The causes are varied affecting both children and elderly. There are congenital vascular paralysis (diabetes mellitus, hypertension or arteriosclerosis), infectious (virus), inflammatory, tumor and trauma.
Before starting treatment, one should assess the systemic involvement of each patient and sometimes other specialists as neurologist, radiologist or oncologist are needed.
Conservative treatment is indicated in the acute phase, during the first 6 months. Through NSAIDs for pain, in the etiology of microvascular occlusion alternately on each eye to avoid diplopia ,and injection of botulinum toxin to minimize contraction of the antagonist.
In chronic or stabilized phase: prisms are used if there is partial recovery and a small residual deviation, but if the deviation is greater and not responding to treatment, surgery should be performed. This arises when the quadrant’s stability has been checked (minimum 6 months) with no signs of recovery. There is no single surgery to solve all cases. The aim is to achieve parallelism in primary gazing position for maximum visual field.
As a condition with multiple causes, is difficult to prevent, but knowing the symptoms and identifying them in both children, adults, and the elderly is of great help in its effective treatment.