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Completed

NCT Number: NCT03109314

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

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.

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Key information

Conditions

Amblyopia Behavior Brain Diseases Central Nervous System Diseases Crowding Eye Diseases Nervous System Diseases Neurologic Manifestations Pathological Conditions, Signs and Symptoms Sensation Disorders Signs and Symptoms Spatial Behavior Vision Disorders

Age range

18 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Phase 4

Primary location

University of California, Berkeley

Berkeley, California, 94720, United States

About this study

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.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

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

Treatment and study plan

Donepezil

Drug

Donepezil will be administered to subjects three days before each training, and during training, to evaluate if donepezil improves the effectiveness of training.

Other names: Aricept

Single-letter training

Behavioral

Subjects will undergo training to identify single letters (10,000 trials, or 10 blocks per session for 10 sessions).

Uncrowd training

Behavioral

Subjects will undergo training to identify letters closely flanked by other letters (10,000 trials, or 10 blocks per session for 10 sessions).

Primary outcomes

  1. Improvement in percent-correct performance in the respective training task

    Time frame: During training (performance will be summarized for each block of trials (a block takes approximately 5 - 10 min to complete). In other words, there should be 100 points of measurements throughout the training period.)

    During training, for each trial, participants' responses can be categorized as correct or incorrect. The investigators will use the percent-correct performance to quantify the performance in each block, and this percent-correct performance will be measured throughout training (i.e. for each block on each day (10 blocks per day), and for 10 training days).

  2. Visual acuity (the smallest letter the participants can see)

    Time frame: Immediately (one day) before and after training

    The change in visual acuity before and after (one day before and one day after) training will be compared. The change will be expressed as a ratio.

  3. Contrast sensitivity for identifying single letters (the lowest contrast required to identify letters)

    Time frame: Immediately (one day) before and after training

    Contrast refers to the smallest difference in luminance between a letter and its background. This is a standard clinical measurement. Essentially, the lowest contrast letter is also the faintest letter that a participant can see. The change in contrast sensitivity for identifying single letters before and after (one day before and one day after) training will be compared. The change will be expressed as a ratio.

  4. Crowding extent (the extent over which adjacent letters will affect the recognition of a letter)

    Time frame: Immediately (one day) before and after training

    Crowding extent refers to the minimum distance between adjacent letters such that the presence of adjacent letters affects the recognition of a target letter. Usually the letter separation will be adjusted until the adjacent letters no longer affects how well the middle letter can be recognized. This distance is the crowding extent. The change in the crowding extent before and after (one day before and one day after) training will be measured. The change will be expressed as a ratio.

Sponsors and collaborators

Lead sponsor

Dennis Levi

Other

Registry information

Official study title

The Effect of Donepezil on Perceptual Learning in Adult Amblyopia

Important dates

Study start
2012
Primary completion
2018
Study completion
2018
First posted
Apr 12, 2017
Registry last updated
Jan 17, 2019

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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