Where is dacryocystitis most likely to cause signs and symptoms?

• A. Medial canthal area of the lower eyelid
• B. Lateral canthal area
• C. Superior eyelid
• D. Conjunctival surface only

Answer: (A)

Dacryocystitis is an infection of the lacrimal sac, which sits in the medial canthal region just behind the lower eyelid. When the sac becomes inflamed, the most noticeable signs appear as swelling and tenderness exactly in that medial canthal area. This location follows the anatomy of the tear drainage system, since the lacrimal sac collects tears from the canaliculi at the inner corner of the eye. If the swelling were in the lateral canthus or the conjunctiva, it would point to other conditions, not lacrimal sac infection. So the medial canthal area of the lower eyelid is the spot where dacryocystitis most often presents.