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Approach to the child with persistent tearing

Authors
Evelyn A Paysse, MD
David K Coats, MD
Michael Cassidy, COT
Section Editor
Richard A Saunders, MD
Deputy Editor
Carrie Armsby, MD, MPH

INTRODUCTION

Nasolacrimal duct obstruction is the most common cause of persistent tearing, infection, and ocular discharge in children. The other causes range from mild, self-limited conditions to sight-threatening ocular emergencies (table 1). Associated signs and symptoms usually help to narrow the differential diagnosis and permit appropriate triage of children with these complaints.

The anatomy of the lacrimal system and the differential diagnosis, evaluation, and treatment for persistent tearing in infants and children are reviewed here. Nasolacrimal duct obstruction and conjunctivitis are discussed separately. (See "Congenital nasolacrimal duct obstruction (dacryostenosis) and dacryocystocele" and "Conjunctivitis".)

ANATOMY OF THE LACRIMAL SYSTEM

The function of tears is to keep the ocular surface moist and flushed clear of debris and bacteria. The tear film is partly responsible for corneal clarity and the transmission of a focused image to the retina.

Tears are produced by the lacrimal and accessory lacrimal glands and drain through the lacrimal drainage system, which begins at the punctum, a small opening on the medial surface of each eyelid (figure 1). The punctum is the opening of the canaliculus, which drains into the common canaliculus and then into the lacrimal sac. There are two canaliculi for each eye. Tears that collect in the lacrimal sac drain through the nasolacrimal duct and into the nose via the inferior meatus, located below the inferior turbinate. The valve of Hasner, a mucosal flap at the distal end of the nasolacrimal duct, prevents air from entering the lacrimal sac when the nose is blown; the valve of Hasner is called the "membrane of Hasner" if it hasn't opened. Tears are swallowed after they pass from the nose into the posterior pharynx.

Tear drainage is both passive and active. Gravity is responsible for passive drainage. Blinking facilitates active drainage by causing negative pressure in the canaliculus and lacrimal sac; the negative pressure draws tears into the lacrimal drainage system [1].

                       

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Literature review current through: Nov 2016. | This topic last updated: Wed Aug 17 00:00:00 GMT+00:00 2016.
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References
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  1. Newell FW. The lacrimal apparatus. In: Ophthalmology: Principles and Concepts, 6th, CV Mosby, St. Louis 1986. p.254.
  2. Lemp MA, Chacko B. Diagnosis and treatment of tear deficiencies. In: Duane's Clinical Ophthalmology, Tasman W, Jaeger EA (Eds), Lippincott-Raven, Philadelphia 1997. Vol 4.