Amblyopia is a condition that results in reduced vision in one of the eyes due to an impaired coordination between the eye and the brain. It is not a result of any eye disease but is marked by a reduction in vision that cannot be corrected by glasses or contact lenses. Although the eye appears normal, it is not being used normally as the brain favors the functioning of the other eye (the good eye). This condition is also sometimes referred to as a“lazy eye”. It is estimated that approximately 1 in 50 children will develop a lazy eye. Generally, children are diagnosed with this condition around the age of four, which means that the child can see less clearly out of one eye and relies more on the “good” eye.
Amblyopia is generally the result of poor visual development during the early years of an individual’s life. It usually occurs before the age of 8. Infants born prematurely or with low birth weight show a greater risk of developing this condition. Brain does not fully acknowledge the images seen by the amblyopic eye. This can be due to a reduction in the amount of light entering the eye, a lack of focus in the eye or confusion between the eyes – where the two images are not the same such as a squint (a condition in which the eyes don’t look in the same direction).
Our eyes function like a camera. An image enters through the lens of each eye and is focused onto the retina which is a light sensitive layer of tissue. The retina translates the image into nerve signals that are sent to the brain. The brain then combines the signals from each eye into a three-dimensional image. The end result of all forms of amblyopia is reduced vision in the affected eye. If left untreated, vision loss occurs due to the improper stimulation of nerve pathways between the brain and the eye.
Three different types of amblyopia:
Strabismic Amblyopia – Strabismic amblyopia develops when the eyes are not straight, wherein the eye may turn in, out, up or down. In such a condition, the brain begins to ignore, or “turns off” the eye that is not straight resulting in the reduced vision in that eye.
Deprivation Amblyopia – Deprivation amblyopia develops when cataracts or similar conditions “deprive” young children’s eyes of visual experience. If not treated very early, these children never learn to see well and can have very poor vision. Sometimes this kind of amblyopia can affect both eyes.
Refractive Amblyopia – Refractive amblyopia is observed in cases where there is a large or unequal amount of refractive error between a child’s eyes in which the brain learns how to see well from the eye that has less need for glasses and does not learn to see well from the eye that has a greater need for glasses. The vision problem may not be easily identifiable as the child does not complain of blurred vision so long as the good eye compensates for the lack of vision in the amblyopic eye. Also, the eye affected with Amblyopia may not look much different from the normal eye. Hence, because the child’s eyes look normal, parents and physician may not suspect that there could be a problem. For these reasons, this kind of amblyopia in children may not be detected until the child has a vision test. This kind of Amblyopia can affect one or both eyes and can be best helped if the problem is detected early.
Amblyopia almost always affects only one eye but may also manifest with the reduction of vision in both eyes. It is estimated that three percent of children under six need amblyopia treatment in India..
During the critical period of a child’s growth i.e., during the first 6 years of life, it is essential for both the eyes to receive clear images. Any interference with clear vision in either eye during the critical period can result in amblyopia (a reduction in vision not corrected by glasses or elimination of an eye turn).
Constant strabismus (constant turn of one eye), anisometropia (different vision/prescriptions in each eye), blockage of an eye due to trauma and lid droop are some of the most common causes of amblyopia. If one eye sees a blur while the other eye is healthy, then the good eye and brain will try to block or suppress the function of the eye with the blur. Amblyopia, therefore, is a process that is neurologically active. The inhibition / suppression process can lead to a permanent reduction in the vision that cannot be corrected with glasses, lenses, or lasik surgery.
Amblyopia can result from any condition that prevents the eye from focusing clearly. It can be an outcome of the misalignment of the two eyes—a condition called strabismus. With strabismus, the eyes can cross in (esotropia) or turn out (exotropia). Occasionally, amblyopia is caused by a clouding of the front part of the eye, a condition called cataract. If not treated early enough, an amblyopic eye may never develop good vision and may even become functionally blind.
A lazy eye does not usually cause symptoms. Younger children are often unaware that there is anything wrong with their vision and, even if they are, they usually fail to describe their condition unlike the older children who may voice their concerns regarding the inability to see clearly through one eye.In some cases one eye may look different from the other. However, this is usually a sign of another condition that could lead to a lazy eye, such as a squint.
The amblyopic eye is not blind – meaning it is not entirely without sight.
Amblyopia affects only the central vision and peripheral vision remains unaffected. A comprehensive eye examination can determine the presence of amblyopia. The earlier it is diagnosed, the greater the chance for a successful treatment.
When amblyopia occurs only in one eye, the good eye takes over and the individual is generally unaware of the condition. That is why it is important to have the child’s vision examined at about six months, at age three and again before he or she enters school.
With early diagnosis and treatment, the sight in the “lazy eye” can be restored. Early amblyopia or lazy eye treatment in India is usually simple, employing eyeglasses, drops,vision therapy, and/or eye patching. Detection followed by correction before the age of two is believed to result in the best outcome. Modern scientific research has disproven the long held belief that children over a certain age (seven or whatever) cannot be successfully treated. Positive effect of therapies in vision improvement in amblyopic or lazy eye conditions in older children and adults have been shown in many clinical studies on brain neuroplasticity in adults.
Amblyopia treatment after the age of 17 is not age dependent but requires more effort including vision therapy. Every amblyopic patient deserves an attempt at treatment. If left untreated, the brain simply pays less and less attention to the images sent by the amblyopic eye. Eventually, the condition stabilizes, and the eye is virtually unused. It is very difficult to effectively treat amblyopia at this point.
Amblyopia can limit the occupational and leisure activities of a person. Activities demanding a good depth perception may be seem hard or impossible for people with amblyopia. In addition, if the good eye gets injured or shows vision problem develops, it may become difficult to carry out the day to day activities normally for a patient with amblyopia.
During the early childhood years, the visual system changes quickly and the visual sight continues to develop.In order to have normal vision, it is important that both eyes develop equal vision. If a child has amblyopia and fails to use his eyes normally, vision development does not occur fully and may even decrease. After the first nine years of life, the visual system is normally fully developed and usually cannot be changed.
If amblyopia treatment is not begun as early as possible, several problems can develop that can seriously affect vision from childhood into adulthood. Some of these complications include the development of serious and permanent visual defect; loss of depth perception (seeing in three dimensions) as 3D vision requires a good vision in both eyes; possibility of a lifetime of poor vision if the stronger eye becomes diseased or injured.
People with amblyopia are more prone to losing vision in the healthy eye due to trauma. If the vision in one eye should be lost later in life from an accident or illness, it is essential that the other eye have normal vision. People who have good vision in only one eye may find they are limited in the kinds of jobs they can perform; thus, making the early detection and treatment of amblyopia a necessity. In amblyopia, treatment success depends upon how early the treatment was initiated.
The treatment procedures at Sanjeevan are designed in such a way that they help the entire visual apparatus (the lens, ciliary muscles, retina and the optic nerve) to relax and re-gain enough strength to recover from Amblyopia. Our treatment helps improve visual acuity with improvement in the three dimensional vision and also depth perception.It also focuses on conditioning the optic pathway of the amblyopic eye.
Since the main causes of Amblyopia are Strabismic – by strabismus (misaligned eyes), refractive – by anisomertropia (high degrees of near sightedness, far sightedness or astigmatism in one or both eyes) and deprivational – by deprivation of vision early in life due to disorders that obstruct the vision such as congenital cataract; we treat the symptoms of each of these causes which mainly arises from optical defect. Hence, we correct the optical defect.
Our treatment helps ameliorate the neural activity in the visual cortex part of the brain. We improve the depth perception, binocular vision and three dimensional vision which are commonly affected in patients with Amblyopia. In addition to this, our treatment process helps increase the blood supply and oxygenation of the retina which in turn helps in the treatment of Amblyopia.