Strabismus involves a misalignment of the eyes, and esotropia is a kind of strabismus, one that involves inward turning of the eyes. The symptoms of esotropia would typically include crossed eyes, double vision, eyes that do not focus or move together, and a loss of vision in one eye as the brain beings to ignore any information coming from it. The last symptom is one that also results in a loss of three-dimensional vision. The causes of esotropia can include damage to the sixth cranial (abducens) nerve or parts of it in the lower brain; a genetic disorder that impairs the nervous system and liver function; the lack of glycerol kinase, which also causes motor problems, bone loss and easy damage and spasticity; a small optic disc and neurological problems. It could be any or all of these, or even a good combination. The problem may involve esotropia that may favor the right eye, left eye or alternate between them. It may also be concomitant or not, which means it could address the question of whether that deviation changes with the direction the person looks in. Concomitant esotropias could begin first, and they could then turn into ‘primary’ ones, but if they occur because of a loss or damage to vision, they are termed secondary. If they are a result of overcorrecting an initial condition wherein the eye was facing outward to start with, they are termed consecutive. Such loss of vision occurs because infants improve their eyesight with use, and without use the eye cannot improve.
Treatment for Esotropia
The origins and the classification for each individual esotrope influence the prognosis of the condition. Treatments almost always start with first identifying internal problems that may have resulted in esotropia to begin with. Thereafter, corrective glasses can be tried, eyes can be blocked to avoid bad vision in otherwise effective eyes to ensure both eyes are used, eye exercises may be used to improve three-dimensional vision, and prisms used to correct vision. In adults, botulin may be used to prevent muscles from contracting before surgery. Phospholine iodide drops have been shown to help deal with the condition. Surgery has also been used to fix muscle tension in one or both eyes. It may even involve the shifting of muscles from the side of the eye to the back; and in some cases by shortening the muscle length to let the eye move outward.