Maculopathy from an accidental exposure to welding arc

Electrical burn-induced vocal cord injury: insights from a case report and literature review

We report a rare case of vocal cord injury from an electrical burn, managed successfully with conservative, non-invasive treatment. This unique case illustrates potential complications of electrical trauma and underscores the need for vigilance and consideration of conservative management approaches.

Derivation of maximum permissive switching time for automatic welding filter based on retinal thermal and blue light exposure limits

Automatic welding filters are intended to protect the eyes of the welder from optical radiation generated by the welding process. Safety standards for automatic welding filters (AWFs) have been developed worldwide. However, switching time requirements have not been studied considering the exposure limits established by the International Commission on Non-Ionizing Radiation Protection (ICNIRP) or the American Conference of Governmental Industrial Hygienists (ACGIH). The aim of this study is to derive the maximum permissive switching time based on ICNIRP guidelines for exposure to intense optical radiation. The single and cumulative exposures associated with retinal thermal and blue light hazards were assessed in the welding environment. The results show that the maximum switching time is inversely proportional to the exponential function of the shade number difference. The proposed maximum switching time, 1/2 to 1/10 smaller than the current ISO, is derived from the effective blue light radiance limits. In addition, an evaluation of the periodic short circuit welding indicates that AWFs do not transmit hazardous levels of radiation in the dark state.

Case series of photic maculopathy associated with exposure to a plasma flash induced by a femtosecond laser

BACKGROUND AND OBJECTIVES

Photic maculopathy resulting from laser-induced plasma flash has been rarely reported, and the corresponding mechanism of the injury is still unclear. We present a case series of three patients with bilateral macular injuries produced by exposure to the plasma radiation from femtosecond laser tightly focusing.

STUDY DESIGN/MATERIALS AND METHODS

Funduscopic findings were accompanied mainly by optical coherence tomography (OCT) investigation of the macula during the follow-up period.

RESULTS

All patients shared similar clinical symptoms soon after the initial injury, including reduced visual acuity and central scotomas. It was acutely characterized by foveolar yellowish faceted lesions upon fundus examination. The main OCT finding in the acute stage was a hyper-reflective area involving all foveolar retinal layers without retinal edema. Repeat OCT evaluation during the latter stages revealed that the retinal changes were reversible, but delineated mild pathology at the outer foveal retina. This retinal structural recovery was accompanied by improvements in visual acuity and central scotomas as well.

CONCLUSIONS

Prolonged viewing of a plasma flash induced by a focused femtosecond laser without eye protection may produce persistent damage to the retina. We believe that a photochemical process similar to the mechanism of a solar burn or welder's maculopathy may cause retinal damage in this case series.

Optical performance of welding curtains and existing standards

Welding curtains and screens are intended to protect workers, other than the welder, from the effects of optical radiation generated by the welding process. The national and international standards for welding screens and curtains have different requirements. The aim is to compare the protection requirements of examples of welding curtain material and to assess compliance with the international and national standards. Spectral transmittance values (ultraviolet, visible, and infrared) of 21 samples were obtained from the records of an ISO/IES 17025 accredited test laboratory and performance/compliance was assessed according to each of the standards. In the ultraviolet, 10 samples passed and seven failed all standards. In the visible/infrared region, four samples passed and 10 failed all standards. Four samples passed the U.S. and international standards but failed the Australian/New Zealand standard in the blue-light transmittance requirement. One sample failed both the U.S. and Australian/New Zealand standards but the result for the international standard was borderline, one sample passed ISO but failed the blue-light requirements, and one failed ISO but passed the blue-light requirements. The derivations of the various requirements are not well documented. The Australia/New Zealand standard is significantly more stringent in the ultraviolet and blue-light regions. A review of the optical radiation hazards and revision of the standards are indicated. It is possible that curtains, other than those tested, that comply with the international standard might transmit hazardous levels of blue light and, conversely, adequate ultraviolet and blue-light protection is available with curtains that do not comply with the international standard.