The lacrimal sac or lachrymal sac is the upper dilated end of the nasolacrimal duct, and is lodged in a deep groove formed by the lacrimal bone and frontal process of the maxilla. It connects the lacrimal canaliculi, which drain tears from the eye's surface, and the nasolacrimal duct, which conveys this fluid into the nasal cavity. Lacrimal sac occlusion leads to dacryocystitis.

Structure:

It is oval in form and measures from 12 to 15 mm. in length; its upper end is closed and rounded; its lower is continued into the nasolacrimal duct. Its superficial surface is covered by a fibrous expansion derived from the medial palpebral ligament, and its deep surface is crossed by the lacrimal part of the Orbicularis oculi, which is attached to the crest on the lacrimal bone.

The lacrimal sac consists of a fibrous elastic coat, lined internally by mucous membrane: the latter is continuous, through the lacrimal ducts, with the conjunctiva, and through the nasolacrimal duct with the mucous membrane of the nasal cavity.

The lacrimal sac connects the superior and inferior lacrimal canaliculi, which drain tears from the eye-surface, with the nasolacrimal duct, which opens into the nasal cavity. The lacrimal sac drains into the nasolacrimal duct via the valve of Krause, which is a fold of mucous membrane at the junction between the lacrimal sac and the nasolacrimal duct.

Function:

The main function of the lacrimal sac is to serve as a reservoir for overflow of tears. The excess tears are pumped inward and outward by the lacrimal sac during blinking with the help of contractions of the lacrimal part of the orbicularis oculi muscle.

Symptoms:

Symptoms of acute lacrimal sac (dacryocystitis) include:

• pain, redness, and swelling in the inner corner of the eye
• watery eye
• swelling in the corner of the eye next to the nose
• eye redness
• pus or mucus in the corner of the eye
• fever

Symptoms of chronic lacrimal sac (dacryocystitis ) are usually milder. You may notice tearing and some discharge from your eye, but little to no swelling.

Causes:

The infection usually starts because of a blockage in the tear duct. Possible causes of this blockage include:

• injury to the nose or eye, such as a broken nose
• growths inside the nose called nasal polyps
• sinus inflammation
• nasal or sinus surgery
• foreign object in the duct
• cancer

Treatment:

The main treatment for lacrimal sac (dacryocystitis) is antibiotics. These drugs kill the bacteria that caused the infection. Usually you take antibiotics by mouth, but if you have a severe infection, you may get them through an IV. Your doctor might also prescribe antibiotic eye drops or ointment.

To relieve pain and swelling from the infection, hold warm compresses to your eye a few times per day.

• Thanks and Regards,
• sarah rose
• Associate Editor 
• journal of eye disease disorders