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Elektromagnetische Bestrahlungsverletzungen der Netzhaut

  • Walter J. Geeraets
  • Ragnit Geeraets
  • Arnold I. Goldman
Article

Zusammenfassung

Drei grundlegende Mechanismen treten nach elektromagnetischer Strahlenschädigung der Netzhaut in Erscheinung. Photochemische Veränderungen, Verbrennungen und nichtlineare Effekte. Absorption findet primär im sichtbaren Wellenbereich statt. Die Primärabsorption verschiedener Wellenlängen geschieht in verschiedenen Gewebsschichten der Netzhaut. Photochemische Veränderungen sind meist unregelmäßig begrenzt wegen der Diffusion toxischer Produkte in die benachbarten Gewebsteile, jedoch sind solche Schäden meist gleichartig innerhalb der geschädigten Strukturen. Wärmeschädigungen haben gewöhnlich ein Zentrum stärkerer Koagulationsschädigungen, da die Temperaturen durch Wärmeleitung zur Peripherie hin abfallen. Nichtlineare Effekte entstehen durch ultrakurze Bestrahlungszeiten mit hohen Energiedichten, wobei Druckwellen, akustische Wellen, hohe elektrische Spannungsfelder und Temperaturerhöhungen mit Dampferzeugung auftreten, die zu Gewebszerreißungen führen. Während die Wellenlänge bei relativ langen Bestrahlungszeiten (d.h. vonμs bis min) zur Erzeugung von Netzhautverletzungen eine große Rolle spielt, ist sie nur von nebensächlicher Bedeutung bei Bestrahlungen mit Ultrakurzzeiten (d.h. von ns und ps).

Electromagnetic radiation damage to the retina

Summary

Basic mechanism involved in electromagnetic radiation damage to the retina are described. Those are photochemical, thermal and non-linear effects. The absorption of radiant energy by the retina occurs primarily in the visible spectral range. Different wave lengths are absorbed in different layers of the retina. Photochemical injury for minimal lesions is uniform and the damaged area may be larger than the irradiated area. Thermal injury for minimal lesions produces usually a more intense central core of damage surrounded by edema. Non-linear effects are caused by ultrashort exposure times and are produced from strong electric fields, acoustic signals, shock waves, etc. generated by high temperature gradients. Wave lenghts play a part in the severity and origin of retinal damage at relative long exposure times but contribute little to retinal injury at ultrashort exposures e.g. psec ranges.

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Copyright information

© Springer-Verlag 1976

Authors and Affiliations

  • Walter J. Geeraets
    • 1
  • Ragnit Geeraets
    • 1
  • Arnold I. Goldman
    • 1
  1. 1.Augenklinik, Medical College of VirginiaVirginia Commonwealth UniversityRichmondUSA

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