Studies reported that tobacco addiction was related to visual impairments, but one unresolved issue is whether the impairments are related to the many compounds existing in the cigarettes or to the effects of nicotine. On the other hand, nicotine gum can be used as replacement therapy or as a neuroprotective agent for some diseases. The main purpose of this controlled trial is to investigate the effects of nicotine gum on vision. The ENIGMA-Vis trial aims to compare two dosages of nicotine gum (2 and 4 mg) and a placebo gum in a randomized, double-blind, placebo-controlled trial of 100 participants to be allocated into a single group assignment of repeated measures (two studies; N = 50 for each one). Eligibility criteria are healthy non-smokers not diagnosed with substance abuse and without an acute or chronic medical condition. Intervention will last three sessions for each participant with a window frame of 1 week per session. Study outcomes are (1) short-term effects of nicotine gum on contrast sensitivity; (2) short-term effects of nicotine gum on chromatic contrast discrimination; and (3) whether demographics, body mass index, or serum cotinine predicts response of visual processing. This study addresses an important gap in the effects of nicotine on vision. One of the main takeaways of this study is to understand the effects of nicotine on contrast sensitivity and chromatic contrast discrimination. This information will provide a further understanding of how nicotine interacts with early visual processes and help determine how the different components present during smoking can affect vision. Clinical Trial Registration Number: RBR-46tjy3.

中文翻译：

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尼古丁口香糖给药对视力的影响 (ENIGMA-Vis)：一项双盲、随机和对照临床试验的研究方案

研究报告称，烟草成瘾与视觉障碍有关，但一个悬而未决的问题是这种障碍是否与香烟中存在的许多化合物或尼古丁的影响有关。另一方面，尼古丁口香糖可用作替代疗法或某些疾病的神经保护剂。该对照试验的主要目的是研究尼古丁口香糖对视力的影响。ENIGMA-Vis 试验旨在在一项随机、双盲、安慰剂对照试验中比较两种剂量的尼古丁口香糖（2 和 4 毫克）和一种安慰剂口香糖，该试验将 100 名参与者分配到重复测量的单组分配中（两项研究；每项研究 N = 50）。资格标准是健康的非吸烟者，没有被诊断为药物滥用，也没有急性或慢性疾病。干预将为每位参与者持续三个会话，每个会话的窗口框架为 1 周。研究结果是（1）尼古丁口香糖对对比敏感度的短期影响；(2) 尼古丁口香糖对色差辨别的短期影响；(3) 人口统计学、体重指数或血清可替宁是否能预测视觉处理的反应。这项研究解决了尼古丁对视力影响的一个重要差距。本研究的主要收获之一是了解尼古丁对对比敏感度和色差辨别的影响。该信息将进一步了解尼古丁如何与早期视觉过程相互作用，并有助于确定吸烟期间存在的不同成分如何影响视力。临床试验注册号：RBR-46tjy3。