scholarly journals Low‐intensity, long‐wavelength red light slows the progression of myopia in children: an Eastern China‐based cohort

Author(s):  
Lei Zhou ◽  
Chao Xing ◽  
Wei Qiang ◽  
Chaoqun Hua ◽  
Liyang Tong
2021 ◽  
Author(s):  
Lei Zhou ◽  
Chao Xing ◽  
Wei Qiang ◽  
Chaoqun Hua ◽  
Liyang Tong

Abstract Myopia is prevalent worldwide, particularly in East and Southeast Asia. Recent studies have suggested that the spectral composition of ambient lighting influences refractive development, especially in humans. We aimed to determine the effect of 650-nm single-wavelength red light on the inhibition of myopia progression in children. In this retrospective cohort study, 105 myopic children (spherical equivalent refractive error [SER], -6.75 to -1.00 dioptres (D)) aged from 4 to 14 years old were retrospectively reviewed. Subjects were treated with 650-nm, low-intensity, single-wavelength red light twice a day for 3 minutes each session, with at least a 4-hour interval between sessions. IOL Master was utilized to measure the axial length (AL) and corneal curvature. Choroidal images were assessed using enhanced depth imaging optical coherence tomography (EDI-OCT), and the luminal area (LA) and stromal area were converted to binary images by the Niblack method. At baseline, the mean SER was -3.09 ± 1.74 D and -2.87 ± 1.89 D at 9 months, and significant changes occurred over time (P = 0.019). The AL increased by -0.06 ± 0.19 mm for 9 months (0.21 ± 0.15 mm pretreatment; P<0.001). The subfoveal choroidal thickness (SFChT) had changed by 45.32 ± 30.88 μm at the 9-month examination (P<0.001). Repetitive exposure to 650-nm, low-intensity, single-wavelength red light effectively slowed the progression of myopia and reduced axial growth after short treatment durations. These results require further validation in a longitudinal study, as well as further research in animal models.


1981 ◽  
Vol 60 (2) ◽  
pp. 453-461 ◽  
Author(s):  
R.P. GILDERSLEEVE ◽  
W.A. JOHNSON

1967 ◽  
Vol 45 (4) ◽  
pp. 525-530
Author(s):  
C. Madhosingh

Growth, pigmentation, and sporophore formation in Lenzites trabea, a polypore fungus, are shown to be affected by differences in light and temperature. Growth occurred under all conditions provided, being greater on liquid substrate than on agar and with maximum mycelium production in continuous red light at 25 °C. Sporophores, however, were formed only under certain continuous fluorescent and red radiations on liquid substrate; and on agar at 15 °C, 20 °C, and 25 °C in darkness broken by occasional brief exposures to low intensity daylight. The growth form under the red radiation and in darkness at 25 °C was similar. The form of fructification varied from poroid resupinate at 15 °C, to somewhat raised structures with larger pores at 20 °C, to an assemblage of discrete upright bodies with lacerated surface at 25 °C. Yellow-brown pigmentation was consistently associated with the fruiting areas in contrast with the predominantly fawn-yellow pigments of the vegetative mycelium. The significance of these results in comparative morphological studies is discussed.


2022 ◽  
Author(s):  
Dingrong Liu ◽  
Zenghua Cai ◽  
Yu-Ning Wu ◽  
Shiyou Chen

Abstract The γ-phase Cuprous Iodide (CuI) emerges as a promising transparent p-type semiconductor for next-generation display technology because of its wide direct band gap, intrinsic p-type conductivity, and high carrier mobility. Two main peaks are observed in its photoluminescence (PL). One is short wavelength (410-430 nm) emission, which is well attributed to the electronic transitions at Cu vacancy, whereas the other long wavelength emission (680-720 nm) has not been fully understood. In this paper, through first-principles simulations, we investigate the formation energies and emission line shape for various defects, and discover that the intrinsic point defect cluster V_I+Cu_i^(2+) is the source of the long wavelength emission. Our finding is further supported by the prediction that the defect concentration decreases dramatically as the chemical condition changes from Cu-rich to I-rich, explaining the significant reduction in the red light emission if CuI is annealed in abundant I environment.


1960 ◽  
Vol 43 (4) ◽  
pp. 723-736 ◽  
Author(s):  
Jack Myers ◽  
C. S. French

Rate of oxygen evolution in photosynthesis was measured as the current from a polarized platinum electrode covered by a thin layer of Chlorella. The arrangement gave a reproducibly measurable rate of photosynthesis proportional to light intensity at the low levels used and gave rapid response to changes in illumination. Two phenomena have been explored. The Emerson effect was observed as an enhancement of photosynthesis in long wavelength red light (700 mµ) when shorter wavelengths were added. Two light beams of wavelengths 653 and 700 mµ when presented together gave a photosynthetic rate about 25 per cent higher than the sum of the rates obtained separately. Large and reproducible transients in rate of oxygen evolution were observed accompanying change in illumination between two wavelengths adjusted in intensity to support equal steady rates of photosynthesis. The transients were found not to be specifically related to long wavelength red light. Both enhancement and the transients have identical action spectra which are interpreted as demonstrating a specific photochemical participation of chlorophyll b.


2011 ◽  
Vol 10 (11) ◽  
pp. 1825 ◽  
Author(s):  
Hitoshi Ishiguro ◽  
Ryuichi Nakano ◽  
Yanyan Yao ◽  
Jitsuo Kajioka ◽  
Akira Fujishima ◽  
...  

Author(s):  
Evgeniya S. Zhukova ◽  
Tatiana G. Shcherbatyuk ◽  
Arseniy L. Potapov ◽  
Irina A. Chernigina ◽  
Vladimir V. Chernov ◽  
...  

Introduction. There is still an open question about the limits of medical use of low-intensity electromagnetic radiation of the optical range in tumor growth due to the risk of increased proliferation of tumor cells. The conditions under which the tumor process is stimulated, as well as the mechanisms of photobiomodulation in oncological pathology, remain unclear. The aim of the study - in vitro evaluation and comparison of the effect of low-intensity electromagnetic radiation with wavelengths of 400, 460 and 660 nm on the activity of free-radical processes in tumor tissue and blood in normal and growing experimental neoplasia. Materials and methods. The study was conducted on biological material obtained from white non-linear rats intact and with subcutaneously transplanted cholangiocellular cancer MS-1. The sources of low-intensity radiation with wavelengths of 400, 460 and 660 nm were led generators. The content of hemoglobin, the activity of superoxide dismutase and catalase, changes in the overall level of free radical processes and antioxidant activity by induced chemiluminescence, and DNA damage by the method of DNA comets were studied. Data analysis was performed using nonparametric statistics methods. Results. The multidirectional effect of radiation with wavelengths of 400, 460 and 660 nm on free-radical homeostasis indicators at the early and late stages of tumor growth, as well as the dependence of biological effects on the wavelength of radiation, was found. Conclusions. The results obtained allow making a number of assumptions about the mechanisms of action of the optical electromagnetic waves on tumor growth, modulating free radical processes in the tumor-bearing organism.


2019 ◽  
Vol 46 (2) ◽  
pp. 146 ◽  
Author(s):  
Trevor Ballard ◽  
David Peak ◽  
Keith Mott

The response of stomata to red and blue light was investigated using small fibre optics (66µm diameter) to control light levels on a single pair of guard cells without affecting the surrounding tissue. Low intensity red light (50µmolm–2s–1) applied to the entire leaf caused stomata to oscillate continuously for several hours with no apparent decrease in amplitude with time. Adding low intensity blue light (50µmolm–2s–1) caused stomata to stop oscillating, but oscillations resumed when the blue light was removed. Adding the same intensity of red light to an oscillating leaf changed the amplitude of the oscillations but did not stop them. When blue light was added to a single guard cell pair (using a fibre optic) in a red-light-illuminated leaf, the stoma formed by that pair stopped oscillating, but adjacent stomata did not. Red light added to a single guard cell pair did not stop oscillations. Finally, blue light applied through a fibre optic to areas of leaf without stomata caused proximal stomata to stop oscillating, but distal stomata continued to oscillate. The data suggest that blue light affects stomata via direct effects on guard cells as well as by indirect effects on other cells in the leaf.


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