Amblyopia that arises due to visual deprivation is especially challenging to treat
Amblyopia or lazy eye is a disorder that ensues following certain ocular abnormalities, namely (A) refractive errors, (B) eye misalignment, and (C) visual deprivation. Most commonly amblyopia arises due to unrecognized refractive errors such as anisometropia, followed closely by eye misalignment in the form of strabismus. Click on the links above to read our detailed description of anisometropic amblyopia and strabismus, respectively. The third wider cause for amblyopia development is visual deprivation with congenital cataract, congenital ptosis, or other rare ocular abnormalities as potential causes.
It is important to note that most cases of amblyopia are caused by either refractive errors and strabismus and that the cases of deprivation are rare. Nonetheless, visual deprivation in early infancy, regardless of the cause, usually results in very deep amblyopia that does not respond well to conventional treatment, which is why appropriate causal treatment (e.g. cataract extraction or ptosis correction) should be initiated soon and prior to any other interventions. In severe deprivation amblyopia then, the cause should be treated before the amblyopia itself.
Anisometropia should be addressed before amblyopia treatment
Conversely, in cases of anisometropic of strabismic amblyopia (i.e. the majority of amblyopias), the answer may not always be that straightforward. As we have discussed extensively in some of our previous blogs, the goal in amblyopia treatment is the improvement of monocular visual acuity as well as binocular visual function – stereovision.
In anisometropic amblyopia, the causal correct refractive correction is often all that is needed as many children respond well to that alone. It leads to the improvement of monocular as well as binocular visual function. Some, however, will not respond well to correct refractive correction alone and will require a form of specific amblyopia treatment, usual occlusion in combination with vision training for maximum effect.
Surgical correction of strabismus – before or after?
In strabismic amblyopia, though, things are usually a bit more complicated. In severe eye misalignment, conventional amblyopic interventions such as occlusion and vision training will usually improve monocular visual acuity, but they will fail to improve stereovision to the desired degree. Therefore, special prism glasses or even surgery will sometimes be needed even before, or during amblyopia treatment.
The truth is, though, that there is no definite answer to whether amblyopia should be treated before, during, or after addressing its cause. It very much depends on the cause, the severity of the cause and the individual. Any form of severe deprivation sure must be addressed before, as should the unrecognized refractive errors. In severe strabismus, on the other hand, the decision whether to correct the squint before, during or after amblyopia treatment lies with the attending physician. Remember, your child’s doctor always knows what is best for you kid!