SW Choi, et al. A CASE OF PHOTIC RETINAL INJURY ASSOCIATED WITH EXPOSURE TO PLASMA ARC WELDING Fig. 7. The dark center of the lesion is surrounded by progres- sively increasing hyperfluorescence in the late phase (white arrow, left eye). Molecules such as interleukins, cytokines, and matrix metallo- proteinases (MMPs) take part in this inflammatory response.1 Although many patients initially complain of pain, glaring, and tears, many of these symptoms fade away after 36 to 72 hours. The advances made in welding techniques have resulted in the increasing use of plasma arc welding and laser welding. Plasma is a highly ionized gas that can conduct electrical current. Matter exists in three phases, solid, liquid, and gas. When enough energy is given to gaseous matter, the tempera- ture of the gas increases dramatically. When more energy is supplied, gas molecules are disintegrated into their compo- nent atoms, atomic structure breaks down, and atoms lose their electrons. Thus, this phase of matter, consists of protons and free electrons. This phase is said to be the fourth phase of matter, or the plasma phase. Plasma arc welding generates a high temperature range of 10,000 to 30,000 degrees Celsius, and can radiate more harmful light beams to the human body that can cause more eye-associated complica- tions than conventional arc welding techniques. Protective goggles containing appropriate lenses are essential. Oliver Arend reported a case of a 26-year-old male with eyes damaged with welding-induced photic retinal injury, even though he wore protective goggles at work. Exami- nation of the lenses in the goggles revealed that they could only absorb light waves with a wavelength less than 380 nm, and could only afford protection against photokeratitis.2 In our case, the patient also wore protective goggles. Although he did not develop complications of the anterior segment such as photokeratitis, he developed and suffered from photic retinal injury. It is known that the findings of fluororescein fundus angio- graphy are usually normal, but a slight defect and aggregation of the retinal pigment epithelium can be observed.3 In our case, ring-shaped paracentral hyperfluorescence appeared simultaneously with a central halo. We suspect it was caused by the partial loss and aggregation of the retinal pigment epithelium. The result of the OCT examination showed no specific signs. In the case of photic retinal injury, histopatho- logically, the outer segment of photoreceptor is the main area of damage.4,5 We believe the extent of the tissue damage was insufficient to be observed by OCT in this case. Although the prognosis of welding-induced photic retinal injury is usually good,6-8 permanent complications are some- times reported.2 Oral steroid treatment for photic retinal injury has been reported, but its effect was unclear. Shahriari et al. suggested that taking vitamin A and aspirin can reduce the risk of developing photic retinal injury.9 Welders must be educated about photic retinal injury and the need to wear proper protective goggles to avoid potential damage to their eyes caused by the vast range of harmful light waves.2 In addition, when patients with welding-induced photokeratitis are encountered in the clinic, they should be provided with a full explanation of the possibilities of photic retinal injury. References 1. Brown J, Planck S, Meshul C, et al. Ultraviolet irradiation induces the production of multiple cytokines by human corneal cells. Invest Ophthalmol Vis Sci 1997;38:2483-90. 2. Arend O, Aral H, Reim M, et al. Welders maculopathy despite using protective lenses. Retina 1996;16:257-9. 3. Freeman J, Gombos GM. Fluorescein fundus angiography in self-induced solar retinopathy. A case report. Can J Ophthalmol 1971;6:124-7. 4. Ham WT Jr, Mueller HA, Rufflo JJ Jr, et al. Basic mechanisms underlying the production of photochemical lesions in the mammalian retina. Curr Eye Res 1984;3: 165-74. 5. Lawwill T. Three major pathologic processes caused by light in the primate retina: a search for mechanisms. Trans Am Ophthalmol Soc 1982;80:517-79. 6. Naidoff MA, Slinkey DH. Retinal injury from a welding arc. Am J Ophthalmol 1974;77:663-8. 7. Romanchuk KG, Pollak V, Schneider RJ. Retinal burn from a welding arc. Can J Ophthalmol 1978;13:120-2. 8. Uniat L, Olk RJ, Hanish SJ. Welding arc maculopathy. Am J Ophthalmol 1986;102:394-5. 9. Shahriari HA, Salari AM, Preventive effects of Vitamin A and Aspirin on the UV light-induced retinopathy in an animal model. Zahedan University of Medical sciences, 98134 Zahedan, Iran. 253