Dr. Burke is one of Cincinnati's most trusted resources concerning amblyopia in children.
What is amblyopia?
Amblyopia is poor vision in an eye that did not develop normal sight during early childhood. The term amblyopia refers to the decreased vision caused when the brain does not receive enough visual stimulation during the critical period from birth through age 8. - the time of life when the sense of sight is developing, maturing, and stabilizing. It is sometimes called “lazy eye." The condition is common, affecting approximately 2 or 3 out of every 100 children. The prognosis is good if amblyopia is discovered and treated early.
What happens to cause amblyopia?
Amblyopia is caused by any condition that affects normal use of the eyes or from any factor that prevents a clear image from being focused inside the eye during the brain's visual development cycle (infancy till 8 years of age).
In amblyopia, the right and left eyes send significantly different qualities of visual information to the brain. The brain learns to depend on the stronger eye for its visual information. If this situation is not corrected, the brain eventually chooses to accept the images from the stronger and ignores or suppresses the images from the weaker eye. The brain's choice usually is made early in childhood when the brain's visual pathways are still developing. This critical period begins at birth and the visual maturation process ends around the age of 8. If amblyopia is not diagnosed and treated within this critical period, the weak eye does not learn to see resulting in a lifelong loss of vision in that eye.
How does vision normally develop?
The brain is born with the wiring diagram for vision but the circuits must be turned on and continually used to stimulate and fully complete the brain’s development. This means newborn infants are born with a potential to see and, as they use their eyes during the first year of life, vision significantly improves. The maximum visual system potential is reached around 2 years of age but the brain's visual development does not become fully mature and stable until around the age of 8.
What are the types of amblyopia?
There are four major types and causes of amblyopia: strabismic amblyopia, deprivational amblyopia, refractive amblyopia, and structural amblyopia. The end result of all forms of amblyopia is reduced vision in the affected eye(s).
What is strabismic amblyopia?
Strabismus (misaligned eyes) is the most common cause of amblyopia. Strabismic amblyopia develops when the brain “turns off” the misaligned eye causing the child to use only the straight eye.
What is deprivational amblyopia?
Deprivational amblyopia develops from any condition or problem that blocks or prevents the normal pathway of light entering the eye thus “depriving” young children's eyes of the normal visual experience. This type of amblyopia may be caused by ptosis, cataract, corneal scarring, and eyelid distortions like that caused by hemangioma.
What is refractive amblyopia?
Refractive amblyopia happens when there is a large or unequal amount of refractive error in a child's eye. Unequal focusing between the eyes (refractive error) is the second most common cause of amblyopia. Typical refractive errors are eye conditions that are corrected by wearing glasses. Amblyopia occurs when one eye is out of focus compared to the other eye. The brain “turns off” the unfocused or blurry eye resulting in amblyopia. Parents and pediatricians may not think there is a problem because the child's eyes may be straight and appear perfectly normal. Also, the “good” eye may have normal vision. For these reasons, this is the most difficult type of amblyopia to detect since it requires careful measurement of vision and may not be found until the child cooperates for a vision screening test.
What is structural amblyopia?
Internal structural abnormalities of the retina or optic nerve may cause amblyopia. When there are congenital or developmental problems of the optic nerve or retina, less and/or blurred information is transmitted to the brain resulting in amblyopia.
Is poor vision always amblyopia?
Poor vision in one eye does not always mean the child has amblyopia. Vision can often be improved by prescribing glasses.
What happens without treatment?
Without proper treatment, the condition may produce profound loss of vision that lasts a lifetime.
When should treatment be started?
Once amblyopia is detected, it should be treated as soon as possible. Amblyopia must be detected and treated as early as possible to maximize vision potential. The earlier in life amblyopia is detected, the easier it is to treat.
Can you treat amblyopia after age 8?
There is an age limit to which amblyopia can be successfully treated. In a previously untreated amblyopic eye, except in rare occasions vision cannot usually be significantly improved in children who were older than 8 years of age.
How is amblyopia detected?
It is not easy to recognize amblyopia. Most children are unaware of having one strong eye and one weak eye. Unless the child has a misaligned eye or some other obvious abnormality, there is often no way for parents to tell that something is wrong. Amblyopia is detected by finding a difference in vision between the two eyes. Vision screening is regularly performed by your pediatrician. Since it is important to detect amblyopia as early as possible, newly developed instruments are available to assist the pediatrician to screen for refractive errors that have a high tendency to cause amblyopia. These instruments are particularly useful in infants and preverbal children.
What determines the success of treatment?
Success in the treatment of amblyopia depends upon how severe the amblyopia was when detected and how old the child was when treatment started. If the problem is detected and treated early, vision can improve for most children. Fortunately, if the decreased vision can be found before age 8, the damage caused by amblyopia may be reversible with treatment. Amblyopia may require treatment until 8 or 9 years of age. After this time amblyopia is very unlikely to recur.
What are the goals of therapy?
In all cases, the goal of amblyopic treatment is to achieve the best possible vision in each eye. While not every child will be improved to normal, most can obtain a substantial improvement in vision.
How do you treat amblyopia?
To correct amblyopia, a child must be made to use the weak eye. Glasses may be prescribed to correct errors in focusing. If glasses alone do not improve vision, then patching or covering the stronger eye is necessary. Occasionally, amblyopia may be treated by partially blurring the vision in the good eye with an eye drop to force the child to use the amblyopic eye.
What are the two steps need to treat amblyopia?
The first step is to insure that clear images are produced in both eyes. When necessary, one of the most important treatments of amblyopia is correcting the refractive error with the consistent use of glasses. The second step is to strengthen the vision in the weaker eye. The mainstay of amblyopia treatment is to force the use of the non-dominant eye by patching the better-seeing eye.
Why don’t glasses fix amblyopia?
With amblyopia, the brain is “used to” seeing a blurry image and it cannot interpret the clearly focused image that the glasses produce. With time, however, the brain may “re-learn” how to see and the vision may improve. When glasses alone do not increase the vision to normal, the better eye is patched to make the amblyopic (weak) eye stronger.
How do you make the amblyopic eye stronger?
The mainstay of treating amblyopia is patching the dominant (good) eye during waking hours. Typically, 2-6 hours per day is necessary but, in some difficult cases, even up to full-time patching may be required. Although this amount of therapeutic patching will frequently improve the vision within a few months, maximal results may take up to a year of patching. Once the vision has improved in the lazy eye there is a small chance that it can worsen again. Therefore, close monitoring will be necessary throughout childhood. On occasion, residual patching of an hour or 2 a day may be necessary until 9-10 years of age to maintain good vision and prevent recurrence of amblyopia. Once vision has been improved, less hours of maintenance patching or less frequent use of the penalizing eye drops may be required to keep the vision from slipping or deteriorating.
What is the most common method to treat amblyopia?
The most common method to strengthen the weaker eye is to have the child wear a patch over the stronger eye for a certain number of hours every day. Your child's progress will be monitored closely requiring frequent eye exams. Once your child's vision has become normal or reached its maximum level of improvement, the patching will be weaned slowly to prevent recurrent visual loss. In selected cases, as an alternative to patching, eyedrops may be prescribed to blur vision temporarily in the stronger eye.
Is patching always successful in treating amblyopia?
In a few cases, treatment for amblyopia may never improve enough to be equal to the vision in the good eye or may not even succeed in substantially improving vision. Patching may be tried for several months (even if no further improvement in vision is noted) to ensure that the child has been given the best chance to develop normal vision. It is hard to decide to stop treatment, but sometimes it is best for both the child and the family. Children who have amblyopia in one eye and good vision only in the other eye should wear safety glasses full time to protect the normal eye from injury.
Is there anything that makes the patching more therapeutic?
Although the most important part of patching is to keep the patch on for the allotted amount of time, there have been reports that the performance of detailed near activities (reading, coloring, hand-held video and computer games) may be more stimulating to the brain and produced better or more rapid recovery of vision.
Is amblyopia inherited?
In many cases, the conditions associated with amblyopia may be inherited. That means parents, siblings, or close family relations may already be known to have amblyopia. Children in a family with a history of amblyopia or strabismus should receive early and regular vision screening.
How do you get the child to patch?
Proper motivation is very important to successful patching. Be positive and encouraging. Make it seem a consistent part of your daily routine. Initially patching may take lots of urging, patience, and one on one stimulation and distraction, since your child will now be using an eye that sees poorly. Many children will resist wearing a patch. Successful patching may require persistence and plenty of encouragement from family members, neighbors, teachers, etc. Children will often throw a temper tantrum but, with parental consistency, persistence, and perseverance, they eventually learn not to remove the patch. Rewards are often useful in the younger child. On the other hand, an older child may be more cooperative or more open to bargaining if patching is performed during certain, desirable activities such as watching a preferred television program or be permitted to play video or computer games.
Do you straighten the eyes before treating amblyopia?
Amblyopic treatment is usually performed before surgery to correct misaligned eyes. Treating the cause alone cannot cure amblyopia. The weaker eye must be made stronger in order for vision to improve. Prescribing glasses or performing surgery can correct the cause of amblyopia, but your pediatric ophthalmologist must also treat the amblyopia. If amblyopia is not treated, a permanent and lifelong visual deficit will be the result.
Patching Compliance - What parents need to know?
Parents must be totally committed. You and your child must adjust to the idea and the reality of wearing an eye patch. It is crucial that you commit to the fact that your child will wear an eye patch. By the tone of your voice and your attitude, you convey to your child that there are no options and that you - the parents - will be in charge of the patch. As with many other difficult situations with children, the three most important ingredients to success are patience (to deal with your child's behavior caused by the their the anxiety caused by patching), persistence (to accomplish the patching goals), and support (for you and your child from your spouse, other family members, and from relatives and friends).
What may you expect from amblyopia therapy?
Your efforts now are likely to result in good (if not normal) vision in the (once) weaker eye for the rest of your child's life. Dr. Burke has been through amblyopic therapy with thousands of patients. The overwhelming number have had excellent results. But you - the parents - must be committed and have perseverance to help your child achieve the best vision result possible.
What types of patches are available?
Patches are of two types: adhesive patches applied directly to the skin and one-sided, slide-on cloth covers used with eye glasses. "Pirate" patches with elastic ties or occluders that clip on the glasses are not recommended.
What if, while wearing the patch, the child has an unusual Head position?
The cause of an unusual head position (head tilt or head turn) while patching is almost always due to peeking around the patch to use the better eye. Obviously this type of “patching” would be of no benefit to the amblyopic eye and this type of behavior must be stopped. A different or improved adhesive patch may help avoid peeking.
What if you need restraints?
If restraints are necessary, custom designed pediatric arm splints are available from MEDI-KID Company at 888-463-3543 or on-line by clicking here.
What activity precautions should be taken?
The vision in the amblyopic eye may be quite poor for a while after beginning the patching therapy, so extra precautions should be taken on stairs, playgrounds, bike rides, etc.
What instructions are there for patching?
Dr. Burke will give you instructions on how to treat amblyopia, but it is up to you, the parents, and your child to carry out this treatment. Children do not like to have their eyes patched, especially since they have been depending on the good eye, that is now being patched, to see clearly. But as a parent, you must convince your child to do what is in their best interest. Successful treatment depends on your commitment and involvement as well as your ability to gain your child's cooperation. Parents play a very important role in determining whether their child's amblyopia will be improved.
Is there an alternative to patching?
As an alternative to patching, eyedrops may be prescribed to “penalize” or blur vision temporarily the focusing ability in the stronger eye which forces the child to use the amblyopic eye.
Does eye drop therapy work for everyone?
Not all children benefit from the eye drop treatment for amblyopia.
What happens when the vision is maximized in the amblyopic eye?
Once vision has been improved, less hours of maintenance patching or less frequent use of the penalizing eye drops may be required to keep the vision from slipping or deteriorating.