**Question:** Most common cause of epiphora in newborn:

A. Epiphora due to blocked nasolacrimal duct
B. Epiphora due to congenital malformation of eyelids
C. Epiphora due to conjunctivitis
D. Epiphora due to strabismus

**Core Concept:** Epiphora is the overflow of tears from the eyes, which is commonly seen in newborns due to a blockage or dysfunction in the lacrimal drainage system. The lacrimal system consists of the lacrimal sac, nasolacrimal duct, and lacrimal gland.

**Why the Correct Answer is Right:** The correct answer is A: Epiphora due to blocked nasolacrimal duct. The lacrimal drainage system is responsible for the drainage of tears from the eyes. In newborns, the most common cause of epiphora is a blockage or dysfunction in the nasolacrimal duct, which leads to an accumulation of tears in the lacrimal sac and subsequent overflow from the eyes.

**Why Each Wrong Option is Incorrect:**

B. Epiphora due to congenital malformation of eyelids (option B) is incorrect because eyelid malformations are less common causes of epiphora in newborns compared to nasolacrimal duct obstruction.

C. Epiphora due to conjunctivitis (option C) is incorrect because conjunctivitis is an inflammation of the conjunctiva and does not directly cause blockage or dysfunction in the lacrimal drainage system leading to epiphora.

D. Epiphora due to strabismus (option D) is incorrect because strabismus is a condition characterized by misalignment of the eyes, which does not directly lead to blockage or dysfunction in the lacrimal drainage system causing epiphora.

**Clinical Pearl:** Congenital nasolacrimal duct obstruction is a common problem in newborns, affecting up to 2% of infants. Management of this condition includes observation, massage of the lacrimal sac, and in persistent cases, endoscopic or surgical intervention may be necessary. The knowledge of this common cause of epiphora in newborns is essential for healthcare providers to accurately diagnose and treat this condition.