Vision Response to Dopamine Replacement

University of Wisconsin (UW)

Status and phase

Terminated

Phase 2

Conditions

Oculocutaneous Albinism

Albinism

Treatments

Drug: Levodopa/carbidopa

Study type

Interventional

Funder types

Other

Identifiers

NCT01663935

2012-0023 (Other Identifier)

2016-1576

Details and patient eligibility

About

The purpose of the study is to evaluate and document physiologic and functional changes in visual performance and retinal function of patients diagnosed with albinism (a dopamine deficiency state) following a trial of oral Levodopa/carbidopa treatment.

Full description

In this study the investigators propose that the retina itself in albinism is deficient in dopamine, and vision improvement will occur as a result of improved retinal function in response to the deficient neurotransmitter dopamine. This study has a pretest-posttest design in order to determine if improvement in vision is in response to replacement of deficiency (dopamine). The electroretinography (ERG) testing and optical coherence tomography (OCT) will be critical determinants to confirm vision improvement as a result of improved retinal function, but are not primary outcome data. Main outcome measures will be collected at pre-treatment, 1 month, 3 months, and 4 months. Change in visual acuity as measured in logMAR by Snellen or sweep visual evoked potential (SVEP) after 3 months of treatment is the primary outcome. Patients include OCA1a patients, OCA1b, OCA2, and unclassified Oculocutaneous albinism (OCA). OCA1a patients clinically are known to have the worst vision, and physiologically have the lowest (or absent) levels of tyrosinase function (Dopamine Production). All patients will be treated with Levodopa/carbidopa 4mg/kg/day in three divided doses.

Enrollment

20 patients

Sex

All

Ages

3+ years old

Volunteers

No Healthy Volunteers

Inclusion criteria

clinical diagnosis of oculocutaneous albinism
age over 3 and weight over 25 lbs.

Exclusion criteria

ocular only albinism
ocular pathology other than albinism
neurologic disease, history of myocardial infarction, history of clinical depression, pregnancy