On Monday I examined 2 children, both of whom are amblyopic. Amblyopia (also called lazy eye) is a condition where one eye sees poorly, even with eyeglasses or contact lenses. Amblyopia can develop in childhood due to:
- An obstruction of vision within one eye due to injury or disease; (deprivation amblyopia)
- Significant differences between the clearness of the images seen by each eye due to farsightedness, nearsightedness or astigmatism; (refractive amblyopia)
- Misaligned eyes or crossed eyes (Strabismus) (strabismic amblyopia).
Both children have refractive amblyopia. M is a 12 year old boy who had been diagnosed with amblyopia many years ago. Treatment consisted of the prescription of glasses for full-time wear and a patching regimen. Patching the better seeing eye for 2 hours per day would force him to use the amblyopic eye while performing visually-guided activities. M’s amblyopia is not too severe. Wearing the patch and performing activities with only the amblyopic eye is probably a little uncomfortable and inconvenient (the cost), but improvements in vision and visual function are likely to be achieved. As the vision in his amblyopic eye improves, so will his binocular skills and depth perception (the benefits).
M was reluctant to wear his glasses, and even more reluctant to comply with the patching regimen. As a result, the vision in his amblyopic eye has improved very little. When I questioned his mother about why he was not wearing the glasses or complying with the patching therapy, she simply said, “he doesn’t like to do it.”
C is a 4 year old boy who failed the vision screening at the pediatrician’s office. As soon as I attempted to cover his better seeing eye to measure his visual acuity, his behaviors and demeanor changed. He tried “peeking” under the patch and when that didn’t work, he tried to take the patch off, and when that didn’t work, he tried to leave the exam room! This child is very myopic in one eye only, and as a result, has severe amblyopia. Even with lenses, he had to be 3 feet away from the Biggest E to see it. The treatment plan for C is the same–the prescription of glasses for full-time wear and patching. However, when he is patched and forced to use only his amblyopic eye, C is very impaired. He will have great difficulty accomplishing any visual tasks when he wears the patch. Using the same analysis, the cost of treatment from the perspective of this 4 year old boy is very high. The severe amblyopia is much more difficult to treat and the prognosis is poor. So while the cost of treatment is high, the expected benefits are low. When I explained this to C’s mother, she began to cry. She understood that although the expected outcomes of treatment are more limited, there are no alternatives. If C’s vision is going to improve at all, he must wear the glasses full-time and wear the patch for several hours every day.
Patching therapy can be very difficult for a family. Young children may not understand why they need to wear the patch and will be reluctant to comply with treatment. They take off the patch as soon as mom or dad turns around. They tilt their heads to try to peek under the patch and use the better eye. They whine. They cry. Patching therapy becomes an ordeal and the parent backs down. As a result, vision does not improve and the amblyopia lingers.
Poor compliance with medical treatment is not unique to the treatment of amblyopia. Patching is a form of medical treatment no different than taking medication or receiving immunizations. I do my best to educate my patients and their parents. I try to be honest about the cost/benefit ratio. But it is up to the parents to make sure the patching therapy is done. Patching requires tough love.
For more information about the treatment of amblyopia, read the Clinical Practice Guidelines published by the American Optometric Association.