What is strabismus?
Strabismus (regardless of age) is a condition in which the eye axes are not parallel or aligned with the object of fixation. They are defined as “adult” when the individual has previously reached a full normal binocular vision. In some ways could be considered “adult” towards the end of the second children’s.
What are the causes of adult strabismus?
Many adults with strabismus already had this condition since childhood, only that in a controlled way, and can make up for it and remain latent. However in the majority of cases have their origin in other diseases, even of a general nature such as:
- Diabetes mellitus
- Thyroid disease (Graves disease)
- Myasthenia Gravis (a neuromuscular disease)
- Tumors of central nervous system
- Cephalic trauma
- Cerebrovascular accidents. Infarction or cerebral hemorrhages
Occasionally loss of parallelism and the affectation of ocular motility may occur after surgery performed on the eye or structures surrounding it. Such as: cataract surgery, surgery of the detachment of retina, eyelid surgery, etc. Due to unwanted involvement of the extraocular muscles during these procedures.
It is necessary to emphasize that a deviation also can take place in an eye with poor vision. In what it is named “a sensory Strabismus”. In this case the patient does not have double vision. Strabismus is a consequence of bad monocular vision and not its cause.
What are the symptoms of adult strabismus?
An adult who develops ocular deviation may experience:
- Visual fatigue
- Double vision (diplopia)
- Overlap of images (confusion of images)
- Sensation of “heaviness”
- Difficulties in the nearby visual activities. Ex. reading.
- Loss of the perception of depth and sensation of volume.
In order to compensate the problem, many adults with strabismus tend to move the head and to take it to a position that relieves its symptoms. This receives the name of: “Ocular crick in the neck”.
Frequently the deviation prevents them from establishing a visual contact with other persons, with both eyes at the same time, what somehow affects its interpersonal relations. It is necessary to remember that the face and in particular the look is the first connection of contact of interaction between two persons. In addition, this condition can affect employment and social opportunities.
How is an adult strabismus treated?
This pathology can be treated with different methods:
- Vision therapy: muscle exercises can be useful in treating a form of strabismus in which the eyes do not can be aligned if on a nearby object (work closely detailed, reading, etc.). This condition is called: “convergence insufficiency”. Close-up view of not only involves focus clearly, but carry both eyes inward so that their axs coincide on the object of attention (books, cursors of computer screen, needle and thread, etc.). This movement of coordinated movement approach and inward is called convergence.
- Glasses with prisms: prisms correctable cause, small deflection angles of minor or moderate diplopias. A prism lens is a transparent, wedge-shaped, which diverts (refracts) the light rays and therefore the images. Do not alter the position of the eyes, but they realign images making them match the visual axs. They relieve the double vision, but they do not correct, if the same the base problem. Often they adhere on the glasses of the patient (like a sticker: Fresnell cousins) and others join already straight in the graduation of the glazing. Prisms are not enough to offset large wide angle deviations due to rigid muscles that have lost their elasticity or with severe paralysis
- Orthoptic exercises
- Botulinum toxin: Applied on muscles with an excess of activity (usually because the muscle that opposes its action has eroded by a paralysis). In these cases often botulinum toxin can stabilize muscle function and relieve symptoms of shunt. This toxin is a substance that is injected in small doses, temporarily paralyzes the muscles. Injected in extraocular muscles, its effects can last several months and often cause permanent changes in the function, thus helping to restore the ocular parallelism using a minimally invasive technique.
- Surgery on the extraocular muscles: surgery on muscles is the most common way to treat a squint. Technically, a squint occurs when some of the muscles surrounding the eye are too weak or too strong. Surgery acts weakening, reinforcing or selectively transposing certain muscles, in order to restore the balance of the binocular
Therefore, surgery can:
- Improve ocular parallelism
- Reduce or eliminate the double vision.
- Improve or restore the combined use of both eyes, referred to as “binocular vision”.
- Reduce eyestrain.
- Expand peripheral vision and binocular visual field.
- Improve the appearance and way of facilitating social relationships and professional opportunities.
Strabismus surgery is usually performed on an outpatient basis using general or local anesthesia according to each case. Postoperative discomfort are usually mild or moderate, and may be relieved with simple painkillers. The conjunctival congestion (which is frequent and normal) reminiscent of a conjunctivitis common and can persist a few weeks. Normally the patient returns is activities common in a few days, even if it is variable according to the degree of complexity of the case. It is important to bear in mind that in a significant percentage of cases, the treatment of strabismus may require more than one surgical procedure to obtain the desired results.
What is "adjustable" strabismus surgery?
In certain circumstances, and in order to obtain a more precise alignment of the eyes, a type of surgery that allows you to refine more accurately the position of the eyes, in the subsequent days the main surgery can be done. The procedure, therefore, occurs in two times.
In the first part (in the operating room) muscles are reset as in classical surgery, but with a kind of special stitches that can adjust and modify the position of the eyes, usually within 24 hours. (in consultation) by placing just a few anesthetic drops.
However, this technique is not applicable to all the cases, nor in any patient, but only if you give very specific conditions.
What are the risks of surgery for strabismus?
The loss of vision associated with strabismus surgery, is extremely rare. However, as in any surgery, there are certain risks:
These complications may include:
- Adverse reactions to anesthetics.
- Decreased vision
- Persistence of the double vision.
- Improper alignment of the eyes.
It is never late to treat a strabismus
An adult must not necessarily live with discomfort and problems caused by the presence of an ocular deviation.
There are multiple medical and surgical therapeutic tools that can greatly help to solve this problem.