The person with cerebral palsy presents a difficulty in maintaining body posture and making movements that can also manifest in their eyes. There are different forms of cerebral palsy depending on the disorders that accompany it, as is the case with associated visual problems. The specific visual difficulties of cerebral palsy derive from sensori-motor alterations of the visual apparatus, the most common are thestrabismus, nistagmus i theocular ataxia. These disorders can occur in isolation or in combination.
Strabismus it is an alteration of the dynamic balance. The eyes cannot maintain parallelism in all or some of the gaze positions. It is due to an imbalance between agonist muscles (act in the direction of movement) and antagonist muscles (act in the opposite direction). Deviation of one eye causes diplopia (double vision). In the adult this circumstance originates a great visual discomfort, similar to vertigo, and a big one insecurity when handling objects or walking. In very young children, the brain is able to set in motion mechanisms to cancel the image coming from the deviated eye and eliminate double vision. With that, the discomfort goes away, though the development of correct binocular vision becomes impossible, which will make it difficult to acquire the feeling of relief and the precise calculation of distances. However, the deleted eye falls into disuse and its visual ability is not developed, resulting in one amblyopia (lazy eye).
El nistagmus is an alteration in which the eyes perform involuntary oscillatory movements i rhythmic. When it is of motor origin it is due to an inability to regulate the tone of the muscles responsible for eye movement. It can occur in one or both eyes, be constant or intermittent, and is very variable in terms of amplitude, direction and type of movement. Sometimes there is a gaze position where movement is minimal or non-existent (lock position of the nistagmus); in this case the person will adopt a position of the head that allows him to look with his eyes in that direction to see as best as possible (compensatory torticollis). In some cases this torticollis further complicates an already difficult body posture.
In theocular ataxia they occur uncoordinated eye movements that escape the person's control. The movements can be in any direction, of both eyes at the same time or of each in different directions. Sometimes it is possible to fix the gaze of one or both eyes at variable time intervals. It is often accompanied by nistagmus.
In addition to these disorders directly related to cerebral palsy can present other visual problems related to the pathological process that has caused the cerebral palsy (cerebral vascular accidents, genetic alterations, infections, trauma, etc.). The most frequent are defects in the visual field (quadrantopsia and hemianopsia) and visual deficit due to damage to the optic pathway (atrophy of the optic nerve, cortical blindness, etc.).
The ophthalmological treatment is aimed at improving the altered functions as a result of the organic lesions. The earlier it is, the better the result because it depends on cortical plasticity to develop new circuits. The ideal age to start it is before the age of 3.
To all these disorders related to cerebral palsy must be added any other visual pathology that may occur in the general population, as well as the natural visual changes associated with the aging of the person.
To conclude, we will say that vision is a complex act that is based on experience. That to be carried out requires the integrity of the visual apparatus and sufficient cognitive capacity to be able to process the experience and transform it into knowledge. I any circumstance that hinders this process will have consequences on visual development and in the psychomotor acquisitions that depend on a correct visual ability to be carried out.
