X-RAY MICROSCOPY 



Fig. 1. View of ciliary body, ciliary processes, 

 pars plana and transition zone toward the choroid 

 (X9). (From Fig. 14 — Francois, Neetens and Col- 

 lette, Ophthalmologica 129: 155 (1955).) 



Fig. 2. Internal wall of Schlemm's Canal 

 (XlOO). Streaks are the canals leading to the white 

 dots which represent the mouth of the openings 

 into the canal. (From Fig. 8 — Francois, Collette 

 and Neetens, Etude Microradiographique de la 

 parof interne du canal de Schlemm. J. Beige, de 

 Radiol., 38, 11 (1955). 



(3) There are no anastomoses between the 

 greater arterial circle of the iris and the 

 choroidal arterial meshwork so that there are 

 no arterioles in the pars plana. This appears 

 to be at variance with the work of Wybar 

 (5) in 1954. 



(4) The existence of two basic vascular 



patterns in the vessels of the optic nerve was 

 established : 



(a) Transverse, having the form of a 

 pentagon, encircling single nerve bundles at 

 regular distances. 



(b) Longitudinal, running in the inter- 

 fascicular spaces in between the bundles from 

 front to back. 



An example of this work is given in Fig. 1, 

 which shows the detail afforded by this tech- 

 nique. 



X-ray microscopy of the vascular system 

 of the eye has been useful and informative, 

 uniquely in the areas other than the retina. 



Aqueous Outflow Apparatus 



Two separate groups of investigators, 

 Frangois, Collette and Neetens (6) and 

 Pattee, Garron, McEwen and Feeney (7), 

 have used x-ray microscopy in an attempt 

 to visualize the outflow channels of the hu- 

 man eye. Other investigators (e.g. Cohan 8, 

 9), have used ordinary radiographic tech- 

 niques for the visualization of radio-opaque 

 material injected into the anterior chamber 

 of the eye. Their results mainly indicated 

 that standard roentgenologic techniques 

 were not suitable and that a further step to 

 microradiography was necessary in order to 

 obtain delineation of some of the structures 

 of the outflow apparatus. 



Frangois et at. (3, 4) used essentially the 

 same technique as they used for their vascu- 

 lar studies. Figure 2 shows the details 

 achieved by this method. 



Refinements of the method were carried 

 out by Pattee et al. (7) . The contrast medium 

 (Thorotrast) was perfused through freshly 

 enucleated eyes under a controlled pressure 

 of less than 25 mm Hg. The eyes were frozen 

 in liquid nitrogen. Small sections were ex- 

 cised from the frozen specimen and lyophil- 

 ized in order to obtain greater contrast. The 

 x-ray apparatus consisted of a Machlett 



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