Pilot Study to Evaluate Levodopa as Treatment for Residual Amblyopia
Condition: Amblyopia
MeSH terms: Amblyopia
Intervention: levodopa/carbidopa; patching; levodopa/carbidopa
Intervention description: Oral levodopa 0.76 mg/kg tid with carbidopa 0.17 mg/kg tid (approximately 4.5 to 1 formulation); 2 hours daily patching; Oral levodopa 0.51mg/kg tid with carbidopa 0.17 mg/kg tid (3 to 1 formulation)
Intervention MeSH terms: Levodopa; Carbidopa
Phase: Phase 2
Study type: Interventional
Primary purpose: Treatment
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Triple (Participant, Investigator, Outcomes Assessor)
Enrollment: 33.0
Sex: All
Minimum age: 8 Years
Maximum age: 17 Years
Healthy volunteers: No
Keywords: Amblyopia; Patching; Levodopa

Summary:

      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.
    

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.