Combining Donepezil With Perceptual Learning in Normal and Amblyopic Human The Effect of Donepezil on Perceptual Learning in Adult Amblyopia

Dennis Levi

Status and phase: Completed; Phase 4

Conditions: Amblyopia

Treatments: Behavioral: Uncrowd training; Behavioral: Single-letter training; Drug: Donepezil

Study type: Interventional

Funder types: Other

Identifiers

NCT03109314

020976_01

Details and patient eligibility

About

The research deals with amblyopia or lazy eye, a condition that affects about 3% of the population, and results in a variety of visual deficits. Recent work suggests that there is limited neural plasticity in the visual system of adults with amblyopia. This study is aimed at understanding and increasing this plasticity. In this study, the investigators aim to understand how the amblyopic brain learns and how this process is affected by a drug called donepezil, which is sometimes given as a treatment for Alzheimer's disease. The investigators hope that this study will help to identify the chemical components that help the brain to learn, as well as the mechanism of amblyopia. The investigators also plan to test the normal periphery, as control.

Full description

The research deals with amblyopia or lazy eye, a condition that affects about 3% of the population, and results in a variety of visual deficits. Recent work suggests that there is limited neural plasticity in the visual system of adults with amblyopia. This study is aimed at understanding and increasing this plasticity. In this study, the investigators aim to understand how the amblyopic brain learns and how this process is affected by a drug called donepezil, which is sometimes given as a treatment for Alzheimer's disease. The investigators hope that this study will help to identify the chemical components that help the brain to learn, as well as the mechanism of amblyopia. The investigators also plan to test the normal periphery, as control.

In this study, donepezil will be administered while amblyopic subjects (or normally sighted subjects tested in the periphery) are trained on a low-contrast single-letter recognition task, or an uncrowd task (recognizing a letter closely embedded within two other letters). Subjects will be asked to identify the target letter (the low-contrast single letter, or the letter embedded within other letters). Training will take place for 10 consecutive days. Pre- and post-tests will be conducted immediately before and after training, and will consist of the measurements of visual acuity, crowding extent and contrast threshold for recognizing single letters.

Enrollment: 20 patients

Sex: All

Ages: 18+ years old

Volunteers: Accepts Healthy Volunteers

Inclusion and exclusion criteria

Subjects with amblyopia

Inclusion Criteria:

• corrected visual acuity being 20/30 or worse in the poorer eye (at least 20/20 in the better eye)
• reduced stereoacuity
• normal retina

Exclusion Criteria:

• with other diagnosed eye diseases

Subjects with normal vision

Inclusion Criteria:

• corrected visual acuity at least 20/20 in each eye
• normal stereoacuity
• normal retina

Exclusion Criteria:

• with other diagnosed eye diseases

Trial design

Primary purpose: Basic Science

Allocation: Randomized

Interventional model: Sequential Assignment

Masking: None (Open label)

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20 participants in 2 patient groups

Single-letter training group

Active Comparator group

Description:

Subjects will be trained on a low-contrast single-letter task. The task is to identify a faint letter (low-contrast). Performance will be measured as correct or incorrect. Training will consist of identifying these low-contrast letters for 1000 trials per day (10 blocks of 100 trials each, subjects can take breaks in-between blocks), for a total of 10 days. During training, subjects will be administered a daily dosage of 5 mg of donepezil. Immediately before and after training (the day before and the day after), subjects' performance on (1) visual acuity; (2) contrast for identifying letters and (3) crowding extent will be measured.

Treatment:

Behavioral: Single-letter training

Drug: Donepezil

Uncrowd training group

Active Comparator group

Description:

Subjects will be trained on an uncrowd task (identifying the middle letter of groups of three letters presented). Performance will be measured as correct or incorrect. Training will consist of identifying these letters for 1000 trials per day (10 blocks of 100 trials each, subjects can take breaks in-between blocks), for a total of 10 days. During training, subjects will be administered a daily dosage of 5 mg of donepezil. Immediately before and after training (the day before and the day after), subjects' performance on (1) visual acuity; (2) contrast for identifying letters and (3) crowding extent will be measured.

Treatment:

Drug: Donepezil

Behavioral: Uncrowd training