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General Thermography
Published in James Stewart Campbell, M. Nathaniel Mead, Human Medical Thermography, 2023
James Stewart Campbell, M. Nathaniel Mead
Sunburn involves a different damage mechanism, quite distinct from thermal burns. Thermal burns are caused by excess infrared (IR) exposure, which can penetrate deeply by conduction. Sunburn is caused by excess ultraviolet (UV) exposure, which does not penetrate the skin deeply or create much heat. UV exposure damages dermal cellular organelles and DNA, causing inflammation. Strong ultraviolet sources other than sunlight can also cause skin damage. Overexposure to a welding arc results in a type of UV burn that appears similar to sunburn, though the distribution over the skin is different. Like welder's burns, overexposure to UV reflecting off snow causes corneal photokeratitis (“snow blindness”) and can damage anatomy not usually affected by sunburn, such as the roof of the mouth or the interior of the nostrils.11
Organization and Management of a Laser Safety Program
Published in Kenneth L. Miller, Handbook of Management of Radiation Protection Programs, 2020
Accident exposure reports overwhelmingly point to lack of user concern for eye protection, wearing wrong eye protection, and purposefully exposing a spectator as reasons for eye damage.19-29 Biological effects in the eye occur in different structures depending on the wavelength of the laser beam and amount of energy absorbed by the structure. Visible and near-infrared wavelengths (400 to 1400 nm) are absorbed by the retina. Radiation that passes through the lens and impinges on the retina has an increased energy of 105 due to focusing by the lens. The “blue light hazard region” includes wavelengths in the 400 to 500 nm range and is named such because of the significant retinal hazard from long-term exposure to these wavelengths. Middle-ultraviolet (200 to 315 nm) and far-infrared (3000 to 106 nm) wavelengths are absorbed by the cornea and can cause photokeratitis. Near-ultraviolet (315 to 400 nm) and middle-infrared (1400 to 3000 nm) wavelengths penetrate further and are absorbed by the lens. These wavelengths may contribute to the production of cataracts.
Potential Health and Nutraceutical Applications of Astaxanthin and Astaxanthin Esters from Microalgae
Published in Gokare A. Ravishankar, Ranga Rao Ambati, Handbook of Algal Technologies and Phytochemicals, 2019
Ambati Ranga Rao, Gokare A. Ravishankar
Astaxanthin showed potent antioxidant and immune responses, which terminate the induction of inflammation in biological systems (EI-Agamy et al. 2018; Park et al. 2018). The structure of astaxanthin is very close to that of lutein and zeaxanthin but has a stronger antioxidant activity and UV-light protection effect (Ranga Rao et al. 2013a; Levy et al. 2018). Astaxanthin di-esters appear to exert influence as synergistic anti-inflammatory agents, increasing the effectiveness of aspirin when the two are administered together (Yamashita 1995). Feeding astaxanthin, Ginkgo biloba extract and vitamin C to asthmat ic animals resulted significantly lowering bronchoalveolar lavage fluid cells and enhanced lung tissues when compared with the anti-inflammatory drug ibuprofen (Haines et al. 2010). Potential anti-inflammatory activity was observed in UV-induced photokeratitis in mice model after oral administration of nanoastaxanthin (Harada et al. 2017). Astaxanthin has also been shown to be beneficial for the treatment of ocular inflammation (Suzuki et al. 2006).
Prospects of topical protection from ultraviolet radiation exposure: a critical review on the juxtaposition of the benefits and risks involved with the use of chemoprotective agents
Published in Journal of Dermatological Treatment, 2018
Nilutpal Sharma Bora, Bhaskar Mazumder, Pronobesh Chattopadhyay
Acute wavelength irradiation between 180 and 400 nm causes an acute photokeratitis with photochemical injury to corneal cells, which initiates with acute inflammation and pain which lasts for 24–48 h. The action spectrum peak is 270 nm. Subclinical photokeratitis starts above energy levels of 30–40 J/m2 at 270 nm and at levels of 100 J/m2 at 300 nm. It has been described after significant UV exposure, for example, in welding, or in extreme/ambient UV-induced stress (snow, ice, watching solar eclipse, etc.) (48). The cornea absorbs the main portion of incident and reflected UVR which makes its cells and stroma are susceptible to UV damage. A characteristic alteration in inhabitants of high altitudes and areas with high UV burden is climatic droplet keratopathy (54), which is characterized by the accumulation of altered proteins in the superficial corneal stroma.
UV-Photokeratitis Associated with Germicidal Lamps Purchased during the COVID-19 Pandemic
Published in Ocular Immunology and Inflammation, 2021
Jesse D. Sengillo, Anne L. Kunkler, Charles Medert, Benjamin Fowler, Marissa Shoji, Nathan Pirakitikulr, Nimesh Patel, Nicolas A. Yannuzzi, Angela J. Verkade, Darlene Miller, David H Sliney, Jean-Marie Parel, Guillermo Amescua
Inadvertent exposure to suprathreshold levels of UV light can unfortunately cause damage to the ocular surface.5 In the normal eye, the cornea absorbs virtually all UV-C rays, which is the shorter and more damaging end of the ultraviolet spectrum, thereby protecting deep ocular structures such as the lens and retina.6 Meanwhile, a greater proportion of UV-A and B are transmitted past the cornea.7 Ultraviolet (UV)-associated photokeratitis is a well-characterized entity in which the corneal epithelium sustains damage from cytotoxic UV energy. Symptoms include variable levels of pain and photosensitivity, which corroborate a spectrum of exam findings, from mild superficial punctate keratitis to severe total epithelial desquamation. Pain experienced by patients is due to sloughing of epithelial cells and exposure of the subepithelial nerve plexus.8 Long duration of exposure, close proximity to the light source, and shorter wavelengths are associated risk factors.9 Putative correlations between UV photokeratitis and prior ocular surface diseases such as dry eye and post-refractive surgery are also suggested.10 UV photokeratitis is typically seen in patients participating in outdoor activities with exposure to direct or reflected natural UV rays, commonly amongst late-season skiers since snow is highly reflective (85%, compared to 1% from grass).11 However, artificial sources of light are also a cause.12–14 Here we report seven cases in which improper use of germicidal lamps purchased during the COVID-19 pandemic lead to UV photokeratitis in patients presenting to the Bascom Palmer Eye Institute.
Ocular toxicology: synergism of UV radiation and benzalkonium chloride
Published in Cutaneous and Ocular Toxicology, 2020
Manlong Xu, Jacob G. Sivak, David J. McCanna
The ambient UV radiation at the Earth’s surface consists mainly of UVA (315–400 nm) radiation and UVB (280–315 nm) radiation10. However, due to ozone depletion, the amount of hazardous UVB radiation reaching the Earth’s surface has increased recently11, posing an additional risk for UV damage to the eye. There is substantial evidence that acute high dose exposure to UV radiation causes photokeratitis and photoconjunctivitis12,13. Also, considerable epidemiological and experimental evidence indicates that chronic exposure to UV radiation is a major risk factor for cataract, pterygium, and age-related macular degeneration12–14.