Amblyopia also known as lazy eye is abnormal vision seen in infancy and childhood. Lazy vision is reduced vision that can affect the visual perception of the child. Actually amblyopia is seen in only one eye, but left untreated it can affect total vision also. Amblyopia can cause loss of vision from mild to severe. It is caused due to reduced neuromuscular communication between the brain and the eyes. The brain receives signal from only one eye and reduced weak signal from the other eye. It ignores the weak signal of the affected eye causing lazy eye. Amblyopia can be corrected with eye patches, eyeglasses or lenses. About 2-3% of American children have amblyopia.
Symptoms :
Since amblyopia begins in infancy or childhood, it is difficult to identify. The baby may have wandering eye that moves either inward or outward. If you grab the attention of the infant by showing some objects, the eyes may not focus together. The baby may have reduced perception in one eye.
If you observe any of the above symptoms in your baby you need to consult your doctor immediately. The child may have blurred vision or turned out vision due to crossed eyes. If there is wandering of eyes after few weeks of birth, you can report it to your primary care physician.
Causes :
The major cause of amblyopia is strabismus or crossed eyes. Babies or children having crossed eyes are likely to develop amblyopia. Misalignment of eyes or reduced communication between the brain and eye muscles can be the cause of amblyopia. Imbalanced muscle would prevent the eyes to track the object together.
You can detect this problem by simply closing one eye of the baby with your hand and check if he/she is comfortable in indentifying favorite toy. If the child cries or fusses and not able to complete the task it can be due to amblyopia. Hereditary is another factor for amblyopia which tends to run in families. Deprivation can block the clear vision of the child causing cloudy or blurred vision. Some children can have astigmatism right from birth which is a refractive error. This can cause vision problems.
Risk Factors :
Children born to parents with vision problems are more prone to develop amblyopia than others. Children with low birth weight and those with a family history of vision problem can develop lazy eye. Amblyopia should be treated without any delay; else it can cause permanent loss of vision.
Diagnosis :
Routine physical exam at primary health care center would reveal any abnormality in the eyes of the infant. Wandering eyes is the strong indication of amblyopia. Your ophthalmologist will examine the baby’s eye through a special device or test his eyes by red reflex test. She would check whether the child has strabismus or crossed eyes. Depending on the age of your child, your doctor may conduct suitable test. Infants are tested using moving object, toddlers by reflex test and preschoolers will be asked to read some letters and identify pictures.
Treatment :
Treatment for amblyopia or lazy eye should begin in early childhood depending on the intensity of the problem. For mild vision abnormality, your doctor may suggest corrective eyewear like eyeglasses or contact lenses, if the problem is due to astigmatism. For some children the doctor may recommend eye patches. The child will have to cover the normal (strong) eye with a patch so that weak eye would outgrow the problem of reduced vision gradually. Children above 4 or 5 years can use this method of treatment.
Eye-drops like atropine can be applied on the strong eye which can cause temporary blurring of vision. The weak eye will be stimulated eventually to focus the object correctly. In severe cases, surgery has to be done for correcting lazy eye or amblyopia. Children having cataracts or droopy eyelid are to be surgically operated for correcting the vision. In some cases, combination of two methods would give the best output in few weeks. Any type of treatment will yield positive results, if started in early childhood.