Amblyopia ("am-blee-oh-pee-ah") is an eye problem that causes poor vision in children. This refers to diminished vision in one or both otherwise anatomically normal eyes.
Reasons for Amblyopia
Amblyobia can happen in young children when there is a big difference in the degree of myopia (minus numbers for distant vision) between the two eyes. The brain ignores the image from the weaker eye to prevent blurred vision. As a result, the weaker eye does not develop properly. This results in decreased or poor vision if the condition is not detected and treated early. Amblyopia results if vision from one eye is consistently suppressed and the other eye becomes dominant.
Undetected myopia before the age of 9 years can lead to amblyopia (lazy eye).
This can also happen when the eyes are not aligned or have 'crossed eyes or strabismus or squint'. The brain then receives two different images, resulting in double vision. In young children the visual system has not reached full maturity and the brain is able to suppress the image from one eye to avoid double vision.
About 5% of children have amblyopia.
Diagnosis of Amblyopia
Since amblyopia usually occurs in one eye only, many parents and children may be unaware of the condition. Far too many parents fail to take their children in for an early vision examination and many children go undiagnosed until they reach a much later age.
The most important diagnostic tools are the special visual acuity tests other than the standard 6/6 or 20/20 letter charts used. Examination with cycloplegic drops can be necessary to detect this condition.
Treatment of Amblyopia
Since there are numerous causes of amblyopia, the treatment must match the problem. Early treatment is usually with the need to use glasses, vision therapy, and/or eye patching. While detection and correction before the age of three is considered to offer the best outcomes, children up to age 9 years can also be successfully treated.
Surgery may be needed for co existing eye conditions such as cataracts, droopy eyelids or crossed eyes.
After the cause of the amblyopia is found, the child will need to use the weaker eye most of the time, so it will get stronger. To make the child use the weaker eye, a patch can be put over the stronger eye. This makes the weaker eye become stronger. Patches may be used all day or part of the day, depending on the child's age and vision.
The treatment usually lasts until vision is normal, or until vision stops getting better. For most children, this takes several weeks.
Eye Patch Therapy
The best results in amblyopia therapy occur when total visual deprivation of the stronger eye is allowed. For this reason, eye patches that stick to the skin around the eye are most effective. Strap-on "pirate's patches" and patches worn over glasses are less effective.
Particularly if a child is resistant to patching therapy, "atropine" eye drops may be helpful in certain conditions. Atropine is instilled onto the dominant eye creating a temporary blurring effect which may allow the child to use the other eye with amblyopia - thus "patching without a patch."
Our ophthalmologist will prescribe the appropriate number of hours that the patch should be worn each day. While undergoing patching therapy, it is critical that your child return for a vision check at the recommended time intervals! This is to safeguard against the development of amblyopia in the eye being patched.
Generally, the younger the child, the quicker the desired results are obtained with amblyopia therapy.
FREQUENTLY ASKED QUESTIONS
What if my child refuses to wear the Patch?
It is not uncommon that children with amblyopia refuse to wear the patch and may also remove it when left unsupervised.
Patching should begin during a time when you can devote all of your attention to your child (e.g. a weekend). Typically, the first few days are the most difficult. Keep your child occupied with games or television when wearing the patch. If your child removes the patch, promptly replace it.
Can surgery correct amblyopia?
No. Surgery may be needed for cataracts, droopy eyelids or crossed eyes.
If not treated, can my child outgrow amblyopia?
No. In fact this may result in permanent irreversible visual loss if untreated
If my child is amblyopic, should his/her siblings be evaluated by an ophthalmologist?
It is reasonable that all siblings of children diagnosed with amblyopia have a routine examination by an ophthalmologist at age 3-4 years
I have been informed of some drugs being used instead of patching?
The only drug treatment I can think of is when some doctors put eye drops (Atropine) in the good eye which makes the vision of this eye hazy, so the child is forced to see with the weaker eye. This works kind of like 'patching' but not very effective as the eye (with drops) still gets stimulated with light. Patching works more effectively in our experience.
How many hours of patching are necessary?
3 hours to 4 hours of 'patching' is what is required to be effective. But this need not be during school hours as some parents' fear that their child will be bullied and can be done at home, when he is doing some activities at home.
What activities would you recommend to help 'exercise' the weak eye?
The recommended games / sports to help stimulate the weak eye include 'ball games or sports requiring a ball such as Tennis, Cricket etc so that this improves his stereoscopic (3 dimensional vision) and body to eye coordination.
Even work such as; doing puzzles improves the linear activity. You may also give him multicolour grains and ask him to segregate the same, string beads in the thread etc.
The doctor may want to give some synaptophore exercises; however, the above exercises will help.
How often does my child need to visit the eye doctor?
Ideally your child has to see the doctor every month or at least once in two months until he achieves 20/20 or 6/6 vision in both eyes. The follow up visits are to check his progress and change any treatment plan that is being followed.
Why is early treatment important?
The vision pathways in the brain must become strong early, when children are very young. The first few years of life are the most important not only for eyesight but since also for development of the brain and ability to learn. After a child is 8 to 10 years of age, the brain's vision system is complete. It cannot develop anymore. If the amblyopia has not been treated by this age, the child will have poor vision for life.