Evaluation of the Lacrimal System

Abstract

The common complaint of a watering eye may be caused by a variety of problems, including lacrimal hyposecretion, lacrimal hypersecretion, or blockage of the lacrimal drainage system. This system is a complex membranous channel whose function depends on the interaction of anatomy and physiology. Effective tear drainage depends on a variety of factors, including the volume of tear secretion, eyelid position, and anatomy of the lacrimal drainage passages. Epiphora is defined as an abnormal overflow of tears down the cheek. The patient with symptomatic tearing may have a normal lacrimal drainage system overwhelmed by primary or secondary (reflex) hypersecretion or a drainage system that is anatomically compromised and unable to handle normal tear production. On the other hand, a patient with partial drainage obstruction may have a concomitant reduction in tear production and therefore be completely asymptomatic or may even suffer from symptomatic dry eye syndrome. Epiphora is determined by the balance between tear production and tear drainage, not by the absolute function or dysfunction of either one. The causes of lacrimal drainage problems can be divided into two categories: anatomic and functional. Anatomic obstruction refers to a mechanical or structural abnormality of the drainage system. The obstruction may be complete, such as punctal occlusion, canalicular blockage, or nasolacrimal duct fibrosis, or partial, caused by punctal stenosis, canalicular stenosis, or mechanical obstruction within the lacrimal sac (i.e., dacryolith or tumor). In patients with functional obstruction, epiphora results not from anatomic blockage but from a failure of lacrimal drainage physiology. This failure may be caused by anatomic deformity such as punctal eversion or other eyelid malpositions, but can also result from lacrimal pump inadequacy caused by weak orbicularis muscle action. It is helpful to determine whether the patient’s complaint is true epiphora or a “watery eye.” Detailed history-taking and careful examination will help direct the evaluation of a tearing eye. A host of clinical tests have been described, and the selection of appropriate tests will depend on the initial history and ophthalmic examination. 13-1-1 History-Taking. Any clinical evaluation should begin with a thorough history. A complaint of watery eye does not necessarily imply a lacrimal drainage problem.