CHAPTER XV. 



GLAUCOMA. 



Glaucoma. — Xortoii defines glaucoma as "an excess 

 of pressure "within the eye, plus the causes of and 

 consequences of that excess." That place where 

 the tissue of the iris, the cellular stroma of the ciliary- 

 body and the posterior and external portions of the 

 cornea and sclera intersect, is known as the iritic 

 angle (see fig. 53). This juncture combines to make a 

 tissue of a fenestrated nature. Tiiese fenestra or 

 openings are the Fontana spaces. The meshes of this 

 tissue (just imagine a coarsely meshed fisher's net) 

 merge into Descemet's membrane and form the liga- 

 ijiention pectinaium hidis. In the sclerotic is formed, 

 by the same means, the canal of Schlemm (see fig. 42), 

 and all of these spaces, etc., are connecting and are of the 

 lymphatics. The caiial of Schlemm communicates with 

 the sclerotic veins, and thus the connection between 

 the anterior chamber and the circulation is established. 

 Blood is never found in these spaces physiologically. 

 The zonule of Zinn, which you remember extends 



from the ciliary processes, (posterior surface) to the 

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