The Effect of Donepezil on Perceptual Learning in Adult Amblyopia
试验速览
- 阶段
- 4 期
- 状态
- 已完成
- 发起方
- 入组人数
- 20
- 试验地点
- 1
- 主要终点
- Improvement in percent-correct performance in the respective training task
研究概览
简要总结
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.
详细描述
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.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Sequential
- 主要目的
- Basic Science
- 盲法
- None
入排标准
- 年龄范围
- 18 Years 至 —（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •corrected visual acuity being 20/30 or worse in the poorer eye (at least 20/20 in the better eye)
- •reduced stereoacuity
- •normal retina
排除标准
- •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
研究组 & 干预措施
Single-letter training group
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.
干预措施: Donepezil (Drug)
Single-letter training group
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.
干预措施: Single-letter training (Behavioral)
Uncrowd training group
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.
干预措施: Donepezil (Drug)
Uncrowd training group
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.
干预措施: Uncrowd training (Behavioral)
结局指标
主要结局
Improvement in percent-correct performance in the respective training task
时间窗: 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).
Visual acuity (the smallest letter the participants can see)
时间窗: 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.
Contrast sensitivity for identifying single letters (the lowest contrast required to identify letters)
时间窗: 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.
Crowding extent (the extent over which adjacent letters will affect the recognition of a letter)
时间窗: 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.
次要结局
未报告次要终点
研究者
Dennis Levi
Professor of Optometry and Vision Science
University of California, Berkeley