Dacryocystitis
Dacryocystitis is an infection or inflammation of the tear sac (i.e., lacrimal sac), which is a small chamber into which tears drain as they leave the eye. Tears function to keep the eyes hydrated and free of debris, viruses, and bacteria. The flow of tears through the lacrimal system begins with tear production by the lacrimal gland beneath the upper eyelids. As fresh tears enter onto the surface of the eye, older tears will flow through small holes, called puncta, in the corners of the upper and lower eyelids into the nasolacrimal sac followed by the tear duct (lacrimal duct) and nasal cavity. Dacryocystitis is most common in infants; however, adults over the age of 40 also have a higher risk of developing dacryocystitis. Common causes in older children and adults may include sinusitis or infection of the sinuses, nasal pus collections, nasal septum deviation, trauma to the nasolacrimal area, and specific ophthalmic and oral medications. Other risk factors include being assigned female at birth, advanced age, and lacrimal sac tumors.