College for Light Medicine and Photobiomodulation, Starnberg, Germany.
ProNeuroLIGHT LLC, Phoenix, AZ, USA.
J Alzheimers Dis. 2021;83(4):1431-1452. doi: 10.3233/JAD-210029.
Photobiomodulation (PBM) involves the use of red and/or near-infrared light from lasers or LEDs to improve a wide range of medical disorders. Transcranial PBM, sometimes accompanied by intranasal PBM, has been tested to improve many brain disorders, including dementia.
To conduct a systematic review according to PRISMA guidelines of pre-clinical and clinical studies reporting the use of PBM, which were considered relevant to dementia.
Literature was searched between 1967 and 2020 using a range of keywords relevant to PBM and dementia. The light source and wavelength(s), output power, irradiance, irradiation time, fluence or total energy (dose), operation mode (continuous or pulsed) irradiation, approach and site, number of treatment sessions, as well as study outcome(s) were extracted.
Out of 10,473 initial articles, 36 studies met the inclusion criteria. Nine articles reported in vitro studies, 17 articles reported studies in animal models of dementia, and 10 studies were conducted in dementia patients. All of the included studies reported positive results. The clinical studies were limited by the small number of patients, lack of placebo controls in some instances, and only a few used objective neuroimaging methods.
The preliminary evidence of clinical benefit, the lack of any adverse effects, and the remarkable ease of use, suggest larger clinical trials should be conducted as soon as possible.
光生物调节（PBM）涉及使用激光或 LED 的红光和/或近红外光来改善多种医疗疾病。经颅 PBM，有时伴有鼻内 PBM，已被测试用于改善多种脑部疾病，包括痴呆症。
根据 PRISMA 指南，对报告使用 PBM 的临床前和临床研究进行系统评价，这些研究被认为与痴呆症相关。
使用与 PBM 和痴呆症相关的一系列关键词，在 1967 年至 2020 年期间进行文献检索。提取光源和波长（s）、输出功率、辐照度、辐照时间、剂量或总能量（剂量）、操作模式（连续或脉冲）、照射方法和部位、治疗次数以及研究结果。
在最初的 10473 篇文章中，有 36 篇符合纳入标准。有 9 篇文章报道了体外研究，17 篇文章报道了痴呆症动物模型的研究，10 篇文章在痴呆症患者中进行。所有纳入的研究都报告了积极的结果。临床研究受到患者数量少、某些情况下缺乏安慰剂对照以及仅少数使用客观神经影像学方法的限制。
临床获益的初步证据、没有任何不良反应以及非常易于使用，表明应尽快进行更大规模的临床试验。
