Strabismus is a sight defect manifested by ocular muscle weakness, which changes the angle of view of one eye in relation to the other eye. The result is a cross-eyed stereoscopic vision disorder.
People with strabismus may have difficulty with driving motor vehicles (eg. cars) and operating machinery and equipment. It may also be difficult for them to play some sports. However it is easier to cope with the activities related to well-developed spatial imagination, eg. working with three-dimensional graphics.
The cause of strabismus may be changes in the development of “fusion center” of the cerebral cortex, including the internal changes of the extra ocular muscles. Appropriate glasses and exercise, or surgery can overcome strabismus.
Strabismus can be caused by amblyopia (“lazy eye”), or impaired vision in one eye. Treatment involves blocking of good eye, thereby forcing the “lazy eye” to work.
Causes of strabismus include:
- ocular diseases
- eye muscle or nerve diseases,
- central nervous system disease,
- genetic factors,
- eye injury.
- crossed eyes
- double vision
- eyes that do not align in the same direction
- uncoordinated eye movements (eyes do not move together)
- vision or depth perception loss
A physical examination will include a detailed examination of the eyes, which include:
- corneal light reflex
- cover/uncover test
- retinal exam
- standard ophthalmic exam
- visual acuity
A brain and nervous system examination will also be performed.
Treatment of strabismus begins by choosing glasses that will correct the refractive error. Eyeglass change should be made, if necessary, on the basis of repeated inspections every six months. Wearing glasses can in some cases cause the disappearance of strabismus.
The next step is to carry out actions to prevent the formation of functional amblyopia. This is achieved by forcing the squinting eye to work harder (See: Amblyopia). These methods are used for children over 4 years of age (due to the possibility of cooperation).
The next stage involves therapeutic enforcing of normal binocular vision. The use of prisms in the treatment of strabismus involves shifting of the image formed on the retina in the desired direction.
Surgical treatment options and outcomes vary depending on the type of strabismus (direction of eye turns, angle of deviations, etc.) It is a one-day procedure and the patient spends only a few hours in the hospital with minimal preoperative preparation.