2020–2021 BCSC Basic and Clinical Science Course™
7 Oculofacial Plastic and Orbital Surgery
Part III: Lacrimal System
Chapter 15: Abnormalities of the Lacrimal Secretory and Drainage Systems
Developmental Abnormalities
Lacrimal Drainage System
Developmental abnormalities of the lacrimal drainage system include
Duplication
In rare cases, multiple puncta and additional canaliculi develop (Fig 15-1). When the extra opening is on the eyelid margin, it may be asymptomatic and requires no treatment. The term congenital lacrimal–cutaneous fistula has been used to describe uncommon fistulas that exit through the skin, typically infranasal to the medial canthus (Fig 15-2). These anlage ducts or fistulas from an otherwise normal canalicular system or lacrimal sac are sometimes asymptomatic, or they may be associated with tears that appear on the skin. Approximately one-third of patients have an underlying NLD obstruction (NLDO); in these cases, chronic mucoid discharge from the affected nasolacrimal sac may be present.
In symptomatic patients, direct surgical excision of the epithelium-lined fistulous tract with direct suture closure is indicated. In patients with underlying NLDO and chronic dacryocystitis, lacrimal intubation or dacryocystorhinostomy may also be required. (See the management subsection in the section Acquired Nasolacrimal Duct Obstruction later in this chapter.)
Aplasia and hypoplasia
Punctal hypoplasia or stenosis is encountered more frequently than true aplasia (Fig 15-3). Management of punctal stenosis, membranes, and aplasia is discussed later in this chapter.
Nasolacrimal duct obstruction
Congenital NLDO is typically due to failure of the duct to fully canalize but can be associated with more severe abnormalities. For example, major facial cleft deformities can pass through or be adjacent to the nasolacrimal drainage pathways and can result in outflow disorders.
Treatment of lacrimal drainage obstruction differs according to the cause and location of the obstruction. Obstruction may involve the puncta, canaliculi, lacrimal sac, or NLD. Because the pathophysiology and management of congenital and acquired lacrimal drainage abnormalities differ, these disorders are addressed separately.
Excerpted from BCSC 2020-2021 series: Section 10 - Glaucoma. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.