Pilot Study to Evaluate Levodopa as Treatment for Residual Amblyopia

This pilot study is being conducted as a prelude to a randomized trial to compare levodopa/carbidopa plus patching versus patching alone. The purpose of the pilot study is to demonstrate recruitment potential, to provide prospective data on the tolerability of levodopa as a treatment for amblyopia, to provide limited data on its safety, to provide limited data on it's efficiency, and to provide data to assist in selecting a dose to use in a subsequent phase 3 randomized trial. In addition, this study will provide the opportunity for investigators to gain experience in using levodopa prior to a randomized trial.

Amblyopia is the most common cause of monocular visual impairment in both children and young and middle-aged adults. Both patching and atropine are accepted treatment modalities for the management of moderate amblyopia in children. Despite best efforts with conventional amblyopia treatment, many older children and teenagers with amblyopia fail to achieve normal visual acuity in the amblyopic eye. In a previous PEDIG study (ATS3) where children 7 to 13 years old were treated with atropine and patching, only 36% of the children with moderate amblyopia and only 23% of the children with severe amblyopia achieved 20/40 or better acuity.

Eligibility Criteria:
Inclusion Criteria:

* Age 8 to \< 18 years old
* Amblyopia associated with strabismus, anisometropia, or both
* Visual acuity in the amblyopic eye 18 to 67 letters inclusive (20/50 to 20/400)
* Visual acuity in the sound eye ≥ 78 letters (20/25 or better)
* Current amblyopia treatment of at least 2 hours patching per day
* No improvement in best-corrected amblyopic eye visual acuity between two consecutive visits at least 4 weeks apart using the same testing method and optimal spectacle correction (if needed), with no improvement of more than 4 letters or one logMAR line.

Exclusion Criteria:

* Myopia more than -6.00 D (spherical equivalent) in either eye.
* Current vision therapy or orthoptics
* Ocular cause for reduced visual acuity

  • nystagmus per se does not exclude the subject if the above visual acuity criteria are met
* Prior intraocular or refractive surgery
* History of narrow-angle glaucoma
* Strabismus surgery planned within 16 weeks
* Known allergy to levodopa-carbidopa
* History of dystonic reactions
* Current requirement to take oral iron supplements including multivitamins containing iron during the 8 weeks of treatment with levodopa-carbidopa
* Current use of antihypertensive, anti-depressant medications, phenothiazines, butyrophenones, risperidone and isoniazid, non-specific monoamine oxidase inhibitors
* Current use of medication for the treatment of attention deficit hyperactivity disorder
* Known gastrointestinal or liver disease
* History of melanoma
* Known psychological problems
* Known skin reactions to patch or bandage adhesives
* Prior levodopa treatment
* Current treatment with topical atropine
* Females who are pregnant, lactating, or intending to become pregnant within the next 16 weeks.

  * A negative urine pregnancy test will be required for all females who have experienced menarche.
  * Requirements regarding the establishment of pregnancy and monitoring of pregnancy over the course of the study as defined by each individual Institutional Review Board may supersede these criteria.