ULTRAVIOLET LIGHT AS A GERMICIDAL AGENT. 

 Experimental Investigation of its Possible Therapeutic Value.* 



f. h. verhoeff, a.m., m.d. 



As is well known, light-waves of sufficiently short wave-lengths are 

 highly germicidal to bacteria suspended in mediums which are trans- 

 parent to these waves. The question has arisen, therefore, whether 

 or not it may be possible to make use of ultraviolet light in the treat- 

 ment of local infections. 



Ultraviolet light has long been successfully used by Finsen in the 

 treatment of certain skin diseases, notably lupus vulgaris, and re- 

 cently has been employed by ophthalmologists in the treatment of 

 vernal catarrh and trachoma, also, it is asserted, with successful results. 

 Its beneficial effect in these conditions, however, obviously is not 

 necessarily due to a direct germicidal action, but possibly only to an 

 irritant action on the tissues. 



Since the cornea compared to other tissues of the body is relatively 

 transparent to ultraviolet light, it follows that if it should prove im- 

 possible by this means to destroy bacteria within corneal tissue without 

 at the same time producing undue injury to the tissue itself, the same 

 negative results would be obtained in the case of all other tissues. 

 For this reason the present investigation was confined to experiments 

 on the cornea. These experiments were made in connection with an 

 investigation by Louis Bell and myself on the effect of ultraviolet 

 light on the normal eye, advantage being taken of the powerful light 

 sources and apparatus therein employed. 



Hertel ^, in 1903, reported the successful use of ultraviolet light in 

 the treatment of corneal ulcers, asserting that here it had a direct 

 germicidal action on the infecting bacteria. He also made some 

 interesting experimental observations in this connection, the most 

 important one from a therapeutic point of view being that he was able 

 to abolish the motility of cholera bacilli enclosed in a quartz cell and 



* Reprinted by permission from the Journal of the American Medical Asso- 

 ciation, March 7, 1914, Vol. LXII, pp. 762-764. 



1 Hertel, E.: Experimentelles liber ultraviolettes Licht, Ber. li. d. 31 Vers, 

 d. ophth. Ges., Heidelberg, 1903, p. 144. 



