|
Untitled Document
Esotropia (inward turning of the eyes) occurs in four types. They are as follows
1. Congenital Esotropia
2. Infantile Esotropia
3. Accommodative Esotropia
4. Partially Accommodative Esotokropia
1. Congenital Esotropia -
Congenital esotropia, or childhood esotropia, is a specific sub-type of primary concomitant esotropia. It is a constant esotropia of large and consistent size with onset between birth and six months of age. Only 23% of infants are born with straight eyes. In majority of cases, one eye or the other actually turns outward during the neonatal period. Within the first three months the eyes regularly come into more steady alignment as coordination of the two eyes together as a team develops.
The cause of the situation is unidentified, and its early onset means that the affected individual’s potential for developing binocular vision is limited. The appropriate treatment approach remains a matter of some debate. Some ophthalmologists support an early surgical approach as offering the best prospect of binocularity at the same time as others remain uncertain that the prospects of achieving this result are good enough to justify the increased complexity and risk associated with operating on those under the age of one year.
Factual congenital esotropia is an inward turn of a large amount, and is present in very few children, but the newborn will not grow out of this turn. Right immature esotropia frequently appears between the ages of 2 and 4 months.
2. Infantile Esotropia –
The baby with infantile esotropia frequently cross fixates, which means that he or she uses either eye to look in the opposite direction. The right eye is used to look towards the left side, and the left eye is used to look towards the right side. By description, they interchange which eye they are looking with. It is further not easy to help this kind of strabismus with non-surgical methods, such as vision therapy and glasses. At times, clear tape applied to the inner third of each lens is able to decrease the tendency to turn inward. Prisms may aid alignment if the turn is not too large.
If the inward turn of the eye is constant, and of a large amount, surgery may be indicated. Both the parent and surgeon have to be committed to multiple procedures to obtain perfect alignment. Improved alignment may look better cosmetically, but it does not necessarily enable the brain to utilize information from both eyes together. Stereopsis, or two-eyed depth perception, is often poor following surgical treatment. The best chance for visual success occurs when the surgeon works with an Optometrist who is comfortable in prescribing glasses and exercises to encourage perfect alignment of the eyes with proper mixture. The possibility of developing binocular vision with surgery on your own diminishes with age. Older children with infantile esotropia might require both surgical interventions, if the turn is large, and vision therapy. Smaller turns can only require vision therapy. Getting the eyes to work together requires a lot of time and effort, but is usually worth it!
3. Accommodative Esotropia -
If excessive inward turning of an eye is first noted around 2 years of age, it may be due to complexity integrating the focusing system with the eye alignment system. Usually when we look across the room or beyond, our eyes are parallel, or straight. Though, when we look at things up close, two things happen. We need to converge more (aim both eyes inward at the same time) and we have to input more focus, or accommodate to keep things clear. Children have large amounts of focusing power, and sometimes in getting things clear, inward turning or esotropia results. If the inward turning only occurs up close, as when playing with small objects, making eye contact, coloring, looking at picture books and so forth, the child may just need glasses for near activities to reduce or eliminate the esotropia.
However, if a child is significantly farsighted (hyperopia), an inward turn of the eye may even occur when focusing to look further away, such as television. If the amount of turn is greater at near than far, your optometrist may prescribe a multifocal lens. For children this could be a traditional bifocal with a line, or a form of no-line bifocal or progressive lens.
"Congenital" means from birth and, using this strict definition, most infants are born with eyes that are not aligned at birth. Only 23% of infants are born with straight eyes. In the majority of cases, one eye or the other actually turns outward during the neonatal period. Within the first three months the eyes gradually come into more consistent alignment as coordination of the two eyes together as a team develops.
Patients with Accommodative Esotropia must never have eye muscle surgery to get rid of the need for glasses. If they do, they will have important focusing troubles when they get older. In the future, these patients might be excellent candidates for refractive surgery or contact lenses. This should be coordinated with the developmental Optometrist and Lasik surgeon.
4. Partially Accommodative Esotropia -
In some instance, part of the inward turn is due to basic esotropia, and an additional amount due to the effect of accommodation. Glasses might decrease the amount of eye turn, but it is not completely compensated. At first, the eye doctor possibly will recommend prism to reimburse for the amount of turn. Office-based vision therapy is frequently desirable. Surgery remains an alternative to address the non-accommodative portion of the esotropia. Remember that surgery on your own hardly ever enables a patient to learn how to use both eyes together as a team, and regularly leaves the patient with poor stereopsis.As vision is a learned process, some form of therapy is often helpful in learning new binocular vision patterns, or restoring normal pathways that have been lost or underutilized. Binocular vision occurs in the visual centers of the brain, not in the eye muscles.
 |
Subscribe to this comment's feed