Sunday, March 14, 2021

Lacrimal Sac Enlargement Case File

Posted By: Medical Group - 3/14/2021 Post Author : Medical Group Post Date : Sunday, March 14, 2021 Post Time : 3/14/2021
Lacrimal Sac Enlargement Case File
Eugene C. Toy, MD, Lawrence M. Ross, MD, PhD, Han Zhang, MD, Cristo Papasakelariou, MD, FACOG

CASE 53
A 3-day-old female is noted to have excessive tearing of the left eye and a small, firm, pea-size mass at the inferior region of the junction between the eye and the nose (oculonasal junction). The mass is not inflamed, and the infant is otherwise in good health and feeding well.

 What is the most likely diagnosis?
 What is the anatomical explanation for this disorder?


ANSWER TO CASE 53:

Lacrimal Sac Enlargement
Summary: A 3-day-old healthy infant has excessive tearing of the left eye and a small, firm, pea-size mass inferior to the medial canthus.

• Most likely diagnosis: Lacrimal sac enlargement (dacryocystocele)

• Anatomical explanation of the disorder: Congenital atresia of ducts draining into or out of the lacrimal sac


CLINICAL CORRELATION
The tear drainage system begins at the lacrimal puncta at the medial portion between the upper and lower eyelids. The puncta open into lacrimal canaliculi, which terminate at the lacrimal sac and, in turn, are drained by the nasolacrimal duct. The nasolacrimal duct develops from a solid cord of cells that recanalizes to establish the lumen of the duct and terminates in the inferior nasal meatus. Atresia of the duct (due to failure to recanalize) occurs in 1 to 3 percent of newborns. Atresia of the lacrimal canaliculi presents with excessive tearing and without a mass. Nasolacrimal duct atresia presents as a mass due to enlargement of the lacrimal sac, and the mass accompanied by excessive tearing suggests atresia of the canaliculi and the nasolacrimal duct. Massage of the nasolacrimal duct region with vigilant monitoring is the usual treatment, and most cases resolve by age 6 months. Persistent obstruction after age 9 months warrants intervention, such as nasolacrimal duct probing. Care must be exercised to avoid creating a false tract. Because the canaliculi and duct are obstructed in this case, duct probing is indicated.


APPROACH TO:
The Lacrimal Gland

OBJECTIVES
1. Be able to describe the anatomy of the lacrimal gland
2. Be able to describe the pathway for drainage of tears from the ocular globe to the nasal cavity

DEFINITIONS
LACRIMAL DUCT PROBING: Outpatient surgical procedure whereby a thin metal probe is used to cannulate the lacrimal duct, which is presumably occluded

DACRYOCYSTOCELE: Enlargement of the lacrimal sac

CANTHUS: Angle formed by the upper and lower eyelids

ATRESIA: Absence of a normal opening due to a developmental defect


DISCUSSION
The lacrimal gland is located in a shallow fossa at the superolateral aspect of the orbit (Figure 53-1). Approximately 12 small lacrimal ducts drain each gland, whose secretions or tears enter the conjunctival sac superolaterally at the superior conjunctival fornix and wash over the surface of the eye in an inferomedial direction, aided by the blinking action of the eyelids. The lacrimal gland is innervated by autonomic nerves, with the secretomotor fibers being a part of CN VII, whereas the sympathetic fibers are vasoconstrictive. Both types of fibers reach the gland through the lacrimal branch of the ophthalmic division of CN V.

Tears accumulate at the medial angle of the eye in the lacrimal lake. At the medial ends of the upper and lower eyelids, a small elevation, the lacrimal papilla, has an opening or punctum that leads to the lacrimal canaliculus. The two canaliculi terminate in the lacrimal sac, a blind-ended membranous structure continuous inferiorly with the nasolacrimal duct. The duct passes through the nasolacrimal canal of each maxilla and terminates in the inferior nasal meatus, the space bounded by the inferior nasal concha. Tears then pass to the nasopharynx and are swallowed.

Lacrimal drainage system

Figure 53-1. Lacrimal drainage system.


COMPREHENSION QUESTIONS

53.1 A 30-year-old woman underwent blunt trauma to the left eye and discovered that she was unable to secrete tears from that eye. Which of the following is the most likely location of the injury?
    A. Medial superior orbit
    B. Medial inferior orbit
    C. Lateral superior orbit
    D. Lateral inferior orbit
    E. Adjacent to nasal bridge

53.2 A clinician places blue dye into the right eye to assess the patency of the tear duct system. Where should one look to see the eventual flow of the dye, assuming the lacrimal duct system is patent?
    A. Superior nasal meatus
    B. Middle nasal meatus
    C. Inferior nasal meatus
    D. Oral cavity
    E. Subclavian vein

53.3 A 5-year-old boy is noted to have severe pain, swelling, and redness around his right eye. He has been diagnosed with periorbital cellulitis with probable spread of the infection to the brain. Which of the following routes best describes the probable avenue of spread to the brain?
    A. Through the cribriform plate into the meningeal space
    B. Facial vein to ophthalmic vein to cavernous sinus into the dural space
    C. Frontal sinus into the sagittal sinus and into the subarachnoid space
    D. Facial canal through the internal auditory meatus to the posterior cranial fossa


ANSWERS
53.1 C. The lacrimal gland, which produces tears, is located in the superior and lateral aspects of the orbit.

53.2 C. The tears flow through the puncta in the medial inferior aspect of the eyelid and travel through the lacrimal duct into the inferior nasal meatus.

53.3 B. Infections involving the periorbital space can penetrate through the ophthalmic vein into the cavernous sinus and into the dural space, leading to meningitis. Thus, prompt antibiotic therapy is critical with this infection.


ANATOMY PEARLS
 The lacrimal gland is located at the superolateral portion of the orbit.
 The parasympathetic secretomotor fibers originate in CN VII.
 Tears are produced by the lacrimal gland and drain through the lacrimal puncta into the lacrimal sac and through the nasolacrimal duct.
 The nasolacrimal duct terminates in the inferior nasal meatus.
 The most common cause of excessive tearing in a newborn is underdevelopment of the lacrimal duct, which is usually treated with expectant management.

References

Gilroy AM, MacPherson BR, Ross LM. Atlas of Anatomy, 2nd ed. New York: Thieme Medical Publishers; 2012:545. 

Moore KL, Dalley AF, Agur AMR. Clinically Oriented Anatomy, 7th ed. Baltimore, MD: Lippincott Williams & Wilkins; 2014:892−893. 

Netter FH. Atlas of Human Anatomy, 6th ed. Philadelphia, PA: Saunders; 2014: plates 83–84.

0 comments:

Post a Comment