Albinism, Oculocutaneous Albinism
Conditions
Keywords
levodopa, Albinism, dopamine, oculocutaneous albinism, vision, retina function
Brief summary
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.
Detailed 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.
Interventions
This study will have an intent to treat goal. Anyone that fits the inclusion criteria for the study will be entered and receive study drug.
Sponsors
University of Wisconsin, Madison
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
TREATMENT
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
3 Years to No maximum
Healthy volunteers
No
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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Visual Acuity Change | 3 months | Change in visual acuity from baseline to 3 months as measured in logMAR by Snellen or Sweep visual evoked potential (SVEP). logMar lower values equals better visual outcome. |
Other
| Measure | Time frame | Description |
|---|---|---|
| Contrast Sensitivity | 3 months | Ancillary testing of visual/retinal function with contrast sensitivity testing. Contrast sensitivity testing measures how well the eyes can distinguish between finer and finer light increments compared to dark. This test is a chart with different capital letters organized in horizontal lines. The contrast decreases with each line. The person will move down the chart to determine the least level of contrast they can see. |
Countries
United States
Participant flow
Participants by arm
| Arm | Count |
|---|---|
| Levodopa/Carbidopa 4mg/kg/Day Treatment drug taken orally three times daily
Levodopa/carbidopa: This study will have an intent to treat goal. Anyone that fits the inclusion criteria for the study will be entered and receive study drug. | 20 |
| Total | 20 |
Baseline characteristics
| Characteristic | Levodopa/Carbidopa 4mg/kg/Day |
|---|---|
| Age, Categorical <=18 years | 15 Participants |
| Age, Categorical >=65 years | 0 Participants |
| Age, Categorical Between 18 and 65 years | 5 Participants |
| Race/Ethnicity, Customized Race/Ethnicity hispanic or latino | 1 Participants |
| Race/Ethnicity, Customized Race/Ethnicity non hispanic or latino/ asian | 3 Participants |
| Race/Ethnicity, Customized Race/Ethnicity Non hispanic or latino/ white | 16 Participants |
| Region of Enrollment Canada | 1 participants |
| Region of Enrollment United States | 19 participants |
| Sex: Female, Male Female | 9 Participants |
| Sex: Female, Male Male | 11 Participants |
Adverse events
| Event type | EG000 affected / at risk |
|---|---|
| deaths Total, all-cause mortality | 0 / 20 |
| other Total, other adverse events | 0 / 20 |
| serious Total, serious adverse events | 0 / 20 |
Outcome results
Primary
Visual Acuity Change
Change in visual acuity from baseline to 3 months as measured in logMAR by Snellen or Sweep visual evoked potential (SVEP). logMar lower values equals better visual outcome.
Time frame: 3 months
Population: participants pre and post treatment per protocol
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Levodopa/Carbidopa 4mg/kg/Day | Visual Acuity Change | .774 logMar | Standard Deviation 0.207 |
Other Pre-specified
Contrast Sensitivity
Ancillary testing of visual/retinal function with contrast sensitivity testing. Contrast sensitivity testing measures how well the eyes can distinguish between finer and finer light increments compared to dark. This test is a chart with different capital letters organized in horizontal lines. The contrast decreases with each line. The person will move down the chart to determine the least level of contrast they can see.
Time frame: 3 months
Population: participants pre and post medication per protocol for contrast sensitivity. Range could be anywhere from a score of 0 to 75 for each eye. The higher the score the more letters they could see in low contrast.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Levodopa/Carbidopa 4mg/kg/Day | Contrast Sensitivity | 23.7 score on a scale | Standard Deviation 21.6 |