7 6 



APPLIED ANATOMY. 



Foreign Bodies in the Orbit. Owing to the considerable space which exists 

 between the eye and orbital walls, large foreign bodies may find a lodgment there, 

 often producing serious symptoms for a considerable length of time. The tang of 



FIG. 90. Lines of the skin incision. (Kronlein's operation for obtaining access to the retrobulbar region.) 



a gun barrel has been so found. This should lead one to search for foreign bodies 

 carefully when this portion of the orbital contents has been wounded. 



Periosteal lining of orbit Incision 



FIG. 91. The rim of the orbit has been divided and the piece of the bone turned outward ; an incision is then made 

 through the periosteal lining. (Kronlein's operation for obtaining access to the retrobulbar region.) 



Emphysema. In cases of fracture involving the inner wall and opening up the 

 nasal cavities or sinuses the air, particularly in blowing the nose, may be forced into 



Periosteal lining Ptump of rectus externus muscle 



Rectus externus cut and turned back 



" Bulb of eye 

 Optic nerve 



FIG. 92. The edges of the incised periosteum have been separated and the external rectus muscle divided, exposing 

 the space posterior to the bulb. (Kronlein's operation for obtaining access to the retrobulbar region.) 



the orbit, distending the lids and producing a peculiar crackling sensation when 

 palpated. No treatment directed to removal of the air is necessary. It is valuable 

 as a diagnostic sign of fracture communicating with the nasal cavities. 



