Table 3.
Studies focusing on the systemic effects of blue light.
| Year | Title | Authors | Subjects | Element of Study | Primary Endpoint | Type of Study | Outcome |
|---|---|---|---|---|---|---|---|
| 2016 | Thin-film optical notch filter spectacle coatings for the treatment of migraine and photophobia | Hoggan et al. [49] | 48 | ipRGC | Headache impact using HIT-6 | Randomized, double-masked, crossover | Positive: Reduction in HIT-6 score + Unexpected result for the 620 nm lenses |
| 2016 | Suppression of vagal cardiac modulation by blue light in healthy subjects | Yuda et al. [50] | 12 | ipRGC | HRV indices—HF, LF/HF | Open-label, Non-Controlled Trial | Positive: Lower HF (greatest with blue light) and increased LF/HF |
| 2017 | Enhancement of autonomic and psychomotor arousal by exposures to blue wavelength light: importance of both absolute and relative contents of melanopic component | Yuda et al. [51] | 10 | ipRGC | Heart rate, HRV indices (HF, LF/HF) + performance of PVT | Open-label, Non-Controlled Trial |
Positive: lower heart rate, HF, and reaction time, but no difference in LF/HF |
| 2017 | Blue and Red Light-Evoked Pupil Responses in Photophobic Subjects with TBI | Yuhas et al. [11] | 36 | ipRGC | Pupil fluctuation | Open-label, Non-Controlled Trial | Negative: no differences between groups regarding blue light |
| 2018 | A Novel Visual Psychometric Test for Light-Induced Discomfort Using Red and Blue Light Stimuli Under Binocular and Monocular Viewing Conditions | Zivcevska et al. [52] | 11 | ipRGC | Light discomfort thresholds | Open-label, Non-Controlled Trial | Positive: greater discomfort for blue light under both monocular and binocular stimulation |
| 2020 | Preference for Lighting Chromaticity in Migraine with Aura | Vieira et al. [53] | 54 | ipRGC | Visual search task | Cross-sectional laboratory study | Positive: visual search time decreased |
| 2021 | Reflexive Eye Closure in Response to Cone and Melanopsin Stimulation: A Study of Implicit Measures of Light Sensitivity in Migraine | Kaiser et al. [54] | 60 | ipRGC | OO-EMG, VDS | Non-Randomized Controlled Trial | Positive: greater OO-EMG activity and visual discomfort for migraineurs |
| 2021 | Assessing migraine patients with multifocal pupillographic objective perimetry | Ali et al. [55] | 62 | ipRGC | Migraine headache diary, mfPOP | Randomized, open-label, crossover | Negative: no differences between used protocols and study groups for the first two aims. Moderate changes for the yellow protocol about their third aim |
| 2021 | Melanopsin hypersensitivity dominates interictal photophobia in migraine | Zele et al. [56] | 23 | ipRGC | EMG, Pupillometry | Non-Randomized Controlled Trial | Positive: lower EMG thresholds and higher PIPR in blue and green light settings |
HRV = heart rate variability; HF = high frequency; LF = low frequency; PVT = psychomotor vigilance test; OO-EMG = orbicularis oculi electromyography; VDS = visual discomfort score; mfPOP = multifocal pupillographic objective perimetry; PIPR = post-illumination pupil response.