The conjunctival sac

What is a conjunctival sac?

The conjunctiva is the boundary between the orbit and the environment and starts at the edge of the eyelid. It lines the inner surface of the eyelids, forms a wrinkle at the bottom and starts again at the cornea. The conjunctival sac (lat.

conjunctival sack) is the area delimited by the fold to the outside and thus represents a cavity surrounded by conjunctiva. It is formed on both the upper and lower eyelid. Due to its good resorption capacity, the lower conjunctival sac can be used to introduce medication into the eye.

The anatomy of the binocular bag

In order to understand the anatomical structure of the conjunctiva, it is necessary to know the structure of the conjunctiva. This is the only way to explain the function and the necessity of the conjunctival sac. The conjunctiva, also called tunica conjunctiva, is a thin, vascular mucosal layer that covers the eyelids from the inside.

Beginning at the edge of the eyelid up to its lowest or highest point, this conjunctiva is called tarsi or simply “eyelid conjunctiva”. This is followed by a fold, the conjunctiva fornicis, and then the conjunctiva runs back in the starting direction as a layer covering the bulb. This is also called the bulb conjunctiva.

It ends by attaching to the corneal surface. The space delimited by the conjunctiva is also called conjunctival sac. Since the conjunctiva is located on both the upper and lower eyelid, the conjunctiva bulbi is divided into a so-called upper and lower conjunctival vault. The lower part is often used to insert certain ointments and medications.

The function of the bindage bag

The conjunctival sac has – besides the extremely practical possibility of inserting different ointments and drops into it – various functions that protect the eye in particular. On the one hand, it ensures that the eyeball remains mobile because it is not fixed to other anatomical structures. Furthermore, it enables both layers of the conjunctiva, the eyelid and the conjunctiva of the bulb, to move against each other with the help of a smear layer of tear fluid. Finally, the conjunctival sac, as a covering fold, provides the perfect climate for the accumulation of lymphocytes. These are defence helpers of the immune system, which ensure that the eye does not fall ill so frequently and is less susceptible to infection.

The diseases of the conjunctival sac

The inflammation of the conjunctival sac is often caused by conjunctivitis. The conjunctiva becomes red, painful and watery, which can cause the conjunctival sac to swell. However, non-infectious inflammation of the conjunctiva and the conjunctival sac also persists.

They are mainly caused by poorly adjusted lenses and overstraining of the eye. Overexertion is mainly caused by working close to the eye when it is not allowed to take a break, or by lack of sleep. But an inflamed gland at the edge of the eyelid can also affect the conjunctiva.

In the case of the inner barleycorn, an inflamed meibomian gland (special sebaceous gland) located at the inner edge of the eyelid and on the conjunctiva is inflamed. A frequent recurrence of these two diseases indicates a weakened immune system, which should be examined more closely by a doctor. The hailstone, also known as chalazion, is a chronic inflammation of the sebaceous gland at the edge of the eyelid.

Due to the slow development of the inflammation, over time a shifting knot develops on the upper and lower eyelid. As a rule, this hardly hurts at all, as it is not a bacterial inflammation, but the body’s own decomposition products in a blocked sebaceous gland. The eye and other structures remain largely untouched and do not swell.

The treatment is mainly carried out by massaging the hailstone, hoping that the congested secretion will drain away. If this does not work, the chalazion is surgically opened and cleared out. The barleycorn is also called hordeolum and is a gland on the eyelid that is inflamed by bacteria.

The most conspicuous symptom is a reddened, painful lump on the edge of the eyelid, which is very sensitive to pressure. The trigger is staphylococci, which can be fought by red light and/or antibiotic ointments. If the inflammation does not disappear on its own, surgical opening by the doctor may be necessary to allow the pus to drain off.

After treatment, the disease usually heals without leaving any residue. Preventive measures mainly include cleaning the hands before touching the eye. This is the only way to prevent the spread of bacteria into this protected space. You can find more information on this topic under: The Barleycorn.