Amblyopia means that the vision in one eye is not as good as the vision in the other eye. This is due to a weakness in the pathways connecting the eyes to the vision centres in the brain.
There are many causes of amblyopia. The main causes include:
Strabismus (crossed or outturned eyes);
Significant refractive errors (severe nearsightedness, farsightedness, or astigmatism)
Partial or full obstruction of visual images reaching the back of the eye, due to cataract, corneal opacity, or droopy eyelid.
Amblyopia is potentially reversible by treating any correctable causes, and then forcing the weaker eye to work harder than the good eye. This treatment is more successful the earlier it is started. In general, it will work well in children less than 8 years of age. In most cases, after age 8-10 years, the vision ‘sticks,’ because the vision pathways mature and become resistant to changes. However, some newer studies are showing promising results in teenagers with amblyopia who were never treated previously. So, earlier is better, but don’t give up too soon!
To stimulate the amblyopic eye, we patch the non-amblyopic eye (the good eye).
Eye patches (brand names are Coverlet, Opticlude, or Ortopad) can be purchased at most drug stores, or here at the office, where we supply more affordable, child-friendly patches. The patches are available in two sizes (junior and regular). Use the larger size (regular) if your child is 2 years or older. The patch should be placed directly on the skin, and must completely cover the normal eye. If prescribed, glasses should be worn over the skin patch. Trying a different type of patch or changing the shape of the patch may relieve skin irritation. The patch can be removed using some warm water to soak off the glue – bath time often works well for this. A pirate patch over the normal eye is not good enough. However, special patches that fit over glasses are available as maintenance therapy, once the vision has improved sufficiently. These cloth patches are available at the office.
Patching should be done during waking hours and preferably during visual tasks (such as reading, drawing, TV, or even video games) performed by your child. Try to avoid patching during nap times to reduce skin irritation. If your child has poor vision in the lazy eye, please avoid unsupervised playing outdoors or in any potentially unsafe area while the normal eye is being patched.
If the child is unable to wear the patch, then we may have to switch to using Atropine eye drops.
Atropine has two effects: One is that it dilates (enlarges) the pupil. This effect can last several days. The second effect is that it paralyzes the focusing muscles to blur the vision. This blurring effect is essential for your child’s treatment and wears off in about 24 hours after the drop is given. Therefore, it is important to use the drops as directed even if the pupil is dilated.
Atropine drops have several side effects, and require certain precautions:
The drops may sting a little.
The pupil will enlarge and the eye may be sensitive to bright light.
The eye may become slightly red.
Your child’s face may become flushed.
If your child develops a fever, you should stop the Atropine drops and give children’s Tylenol.
Please keep the Atropine OUT OF REACH OF CHILDREN, as there is enough medicine in the bottle to seriously harm any child who ingests the contents. If you are concerned regarding ingestion, call Poison Control at 403-944-1414, or Health Link at 811.
Be sure to wash your own hands before and after administering the drop to ensure that you do not contaminate your child’s other eye or your own.
If you have any concerns about the Atropine drops, stop using the drops and call our office the next working day.
Regular follow-up visits are essential throughout amblyopia treatment, to be sure that all is going well. A small number of children can develop strabismus (misalignment) of their eyes which becomes unmasked by the use of Atropine or patching. Also, the vision in the normal eye can decrease a small amount as a side effect.