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Abstract #17150 Published in IGR 9-1
Irritation by light
Hommer K; Gerstenbrand F; Widder W; Resch H; Hommer ASpektrum der Augenheilkunde 2006; 20: 267-271
BACKGROUND: Irritation by light is an especially delicate form of environmental pollution. The senses- of smelling, of taste, of hearing and of sight, but also the skin are affected by it. Proportionate stimuli within physiological limits are necessary for orientation and for the mayor vegetative functions and processes. However, the general rule that the dose determines the difference between usefulness and damage applies here, too. The subjection of the senses of sight by continuous stimuli is a serious problem, not only for the eyes themselves, but also concerning the transmission and processing in the central and the vegetative nervous system. DEVELOPMENT: In the early epoch of the evolution of mankind lighting conditions were rather constant. In those times when the duration of life was short as a rule, light-induced eye diseases hardly occurred, except for cases of keratopathia photoelectrica or retinopathia solaris. Only the invention of the incandescent lamp by Goebel, and respectively by Edison (1879) brought more and more bright light 'into the world'. According to Marshall, the production of electric light kept within moderate limits until 1945. Since than there has been a steep, almost exponential increase. The light-giving lamps were strengthened in a sophisticated way and adapted to the various requirements. Made more resistant, they emit increasingly aggressive, short-wave light. PHYSICAL FUNDAMENTALS: The energy of the single photon is directly proportional to the frequency. Therefore, the blue light bleaches the visual substances more radically than red light does - formerly this was taken into account by developing the Trendelenburg - spectacles of the radiologists. In dim media, but also in cases of dimming of the lens or the cornea blue light, as Tyndall has pointed out, is diffused five times more strongly than red light. This phenomenon is called Ray-leigh diffusion (1871). MORPHOLOGICAL CHANGES: Epidemiological data, but also the results of animal tests indicate that medical exposure especially to short wave blue light is apt to accelerate degenerative diseases of the retina. The possibility of glaucoma damage as a result of excessive light is under discussion. Reme et al. found out in animal experiments that green light (550 nm) does not cause a morphologically ascertainable effect. On the other hand, blue light (403 nm) produces cell death of photoreceptors due to apoptosis. CONCLUSION: It is the duty of the ophthalmologist both to treat eye diseases and to prevent them. Therefore energetic measures must be taken to avoid increasing stress on human eye, especially by short-wave lights (Xenon projectors, sun-tan studios, etc.). LA: German
Dr. A. Hommer, Krankenanstalt Sanatorium Hera, Loblichgasse 14, 1090 Wien, Austria. a.hommer@aon.at
Classification:
9.2.2 Other risk factors for glaucoma (Part of: 9 Clinical forms of glaucomas > 9.2 Primary open angle glaucomas)
