LACRIMAL SYSTEM

- Epiphora

It means abnormal flow of tears outside the eye. By means of the “zip-closure action” of the blinking of the eyelids, tear fluid is moved towards the medial canthus. If any functional obstruction to its

drainage or simply excessive production, tears flows over the edge of the eyelid and a brown tear stripe will form under the medial canthus.

Causes:

1-   Medial lower entropion.

2-   Prominence of the globe (exophthalmia) with shallow lacrimal lake.

3-   Obstruction of the lower punctum.

4-   Congenital absence of the lower punctum or canaliculus.

5-   Nasolacrimal duct obstruction.

6-   Localized inflammation along the course of the duct.

7-   Excessive tear production secondary to irritation caused by entropion, ectropion, distichiasis, trichiasis and ectopic cilia.

Symptoms:

Flow of tears outside the eye with tear stains the medial canthal skin and hair. Flow of tears for a long time usually leads to formation of tear scald in donkeys.

 Treatment:

Try to correct the primary cause after thorough examination of the eyeball and its adnexal structures.