456 CLINICAL APPLIED ANATOMY. 



cornea being irritated by the lashes, with consequent ulceration, 

 or pannus. 



Ectropion. Ectropion may be due to atrophy of the palpebral 

 portion of the orbicularis or to cicatricial contraction. Eversion 

 of the lower eyelid leads to a faulty position of the lower punctum 

 lachrymale, and therefore to epiphora. 



Epiphora. The overflowing of the lachrymal secretion from 

 the conjunctival sac down the cheeks, which is termed epiphora, 

 may be physiological or pathological. 



The lachrymal apparatus consists, firstly, of the secreting 

 organ, the lachrymal gland. This is situated in the upper, 

 outer and anterior part of the orbit, resting up against a hollow 

 in the orbital surface of the frontal bone. It is invested in a 

 capsule of fascia which separates it from the rest of the orbital 

 space. The ducts of the gland are from twelve to fifteen in 

 number, and open at the fornix, or reflection, of the conjunctiva 

 beneath the upper lid. The gland is supplied with blood by the 

 lachrymal artery, a branch of the ophthalmic, and with secretory 

 stimulation by the lachrymal nerve, a branch of the first division 

 of the fifth cranial nerve. It is over-stimulation of the gland 

 through this nerve, usually reflexly, which induces physiological 

 epiphora, the drainage apparatus being unable to cope with the 

 superabundance of tears. It is possible to remove the gland for 

 tumour, over-action, incurable epiphora, or other reason without 

 invading the general cavity of the orbit. 



The secondary part of the lachrymal system consists of the 

 drainage apparatus for conveying the secretion of the gland out 

 of the conjunctival sac into the nose. Each eyelid near the 

 inner canthus is provided with a minute aperture, the punctum, 

 that in the upper lid, however, being almost functionless. Each 

 punctum rests normally against the ocular conjunctiva, and 

 receiving the lachrymal secretion which has flowed across the 

 front of the eyeball, passes it on into two small channels, the 

 canaliculi, one in each lid. At first these are almost vertical 

 in direction, then, making a sudden bend, they run almost 

 horizontally inwards, above and below the caruncle, to open 



