54 SURGICAL APPLIED ANATOMY. [Chap. iv. 



or five main trunks (venoe vorticosse), which pierce the 

 sclerotic midway between the cornea and the optic 

 nerve. In the choroid they lie external to the 

 arteries. 



2. The two long ciliary arteries (from the 

 ophthalmic) pierce the sclerotic to the outer side 

 of the optic nerve, and run forwards, one on either 

 side, until they reach the ciliary region, where they 

 break up into branches that, by anastomosing, form a 

 vascular circle about the periphery of the iris (the 

 circulus major). From this circle some branches pass 

 to the ciliary muscle, while the rest run in the iris in 

 a converging manner towards the pupil, and at the 

 margin of the pupil form a second circle (the circulus 

 minor). 



3. The anterior ciliary arteries (from the muscular 

 and lachrymal branches of the ophthalmic) pierce 

 the sclerotic (perforating branches) about a line 

 behind the cornea, join the circulus major, and give off 

 branches to the ciliary processes, where they form 

 copious anastomosing loops. These arteries lie in the 

 subconjunctival tissue. Their episcleral, or iion-per- 

 forating branches, are very small and numerous, and 

 are invisible in the normal state </ the eye. In 

 inflammation, however, of the iris and adjacent parts, 

 these vessels appear as a narrow pink zone of fine 

 vessels round the margin of the cornea, that run 

 nearly parallel to one another, are very closely set, 

 and do not move with the conjunctiva. This zone is 

 known as the zone of ciliary congestion, or the circum- 

 corneal zone. 



4. The vessels of the conjunctiva are derived from 

 the lachrymal and two palpebral arteries. These 

 vessels, in cases of inflammation, are readily dis- 

 tinguished from those last described. They are of 

 comparatively large size, are tortuous, are of a bright 

 brick-red colour, can be easily moved with the 



