Optometric Management of Anisometropic Amblyopia
Ph.D. in Optometry and Vision Sciences
As primary eye care practitioners, we are the first to diagnose and treat a variety of ocular conditions. The role we play becomes even more vital in our youngest patients. Amblyopia is a frequent cause of monocular vision loss in children. A difference in refractive error between the two eyes (anisometropia) is a common cause of amblyopia.
Although there have been reports that refractive correction alone results in improved vision in anisometropic amblyopia, it is generally held that the majority of cases will need additional treatment because refractive correction alone will not be sufficient to completely treat the amblyopia. In one study, approximately one-third of children ages three to under seven with anisometropic amblyopia resolved their amblyopia with spectacle correction alone, and over 75% of patients improved two or more lines of visual acuity with spectacle correction alone.
The next step in amblyopia treatment is penalization of the better-seeing eye. This can be achieved by a variety of methods, the most common being patching or atropine use to blur the sound eye. Patching for two hours per day is recommended for patients with moderate amblyopia (20/80 or better visual acuity), while patching for six hours is recommended for patients with severe amblyopia (20/100 or worse visual acuity).
Another treatment currently under investigation is the use of binocular therapy to treat amblyopia. One approach is to use dichoptic stimuli, in which the amblyopic eye views a high contrast image and the fellow eye views a lower contrast image. This therapy has been implemented using games on an iPad and by having patients view movies with this type of stimulus.
In summary, amblyopia can initially be managed in a primary care setting. Many patients will improve their visual acuity, some to the point of resolution, with correction only or with correction and optical penalization. Patients whose amblyopia does not resolve with correction and penalization, as well as patients with strabismus, can be referred to a specialist in binocular vision for further treatment. Proper diagnosis and management of amblyopia in a primary care setting is important to providing amblyopic patients the best care and the best possible visual outcomes.