544 



WERNER K. NOELL 



OUTER S. 



INNER S. 



NUCLEUS 



SYNAPSE 



Fig. 1. Rod cell of the mammalian retina. Outer S, outer segment; Inner S, inner 

 segment; cc, connecting cilium (De Robertis, 1956); mi, mitochondria; rf, rod fiber. 

 The shaded area denotes Miiller cells, which, like the glia cells of brain, fill the 

 spaces between the neuronal elements of the retina. 



glycolysis, and of oxygen at high pressure. The histopathology of x-irradiation 

 is principally the same as observed in these cases; however, in several other 

 respects, the retinal effect is very different. 



Our x-irradiation studies, principally on the adult albino rabbit, were 

 performed mainly with Dr. Norman Baily, now of Los Angeles. They will be 

 presented more extensively in the near future. The action of various forms of 

 x-irradiation on the retina was followed by electroretinography, and a corre- 

 lation was attempted between effects on fimctional capacities, structure, and 

 metabolism. 



Procedure 



The main methods used have been outlined by Baily and Noell (1958). 

 The x-ray beam passed through the head of the rabbit in the main axis of 

 both eyes, entering through the cornea of the close eye and passing out 

 through the cornea of the distant eye. To minimize radiation damage to 

 surrounding tissues, the smallest field size consistent with the necessity for 

 uniform radiation intensity over the entire entrance region was employed. 

 Eyes and x-ray beam were carefully aligned, so that every experiment was 

 identical. The x-ray beams were produced by self-rectified generators operat- 

 ing at 100, 250, and 2,000 kv peak potential (kvp) . 



Because of the peculiar geometry of the eye, precise experimental deter- 

 mination of the distribution of the absorbed dose throughout the retina was 

 not possible. It was felt that the best solution was to combine the knowledge 

 of standard depth dose curves with certain experimental determinations 

 described by Baily and Noell (1958), to obtain the dose at the various 

 regions of the retina. 



The retina covers the major portion of a spherical shell, thereby condi- 

 tioning different doses for different regions. Our results concerning effects of 



