This video demonstrates lacrimal probing and irrigation to investigate the anatomy, patency, and functional status of the lacrimal drainage system.
Procedure: This video demonstrates lacrimal probing and irrigation to investigate the anatomy, patency, and functional status of the lacrimal drainage system.
Introduction: The lacrimal drainage system consists of the puncta, canaliculi, lacrimal sac, and the nasolacrimal duct. A variety of pathologies can occur in this system, including infection, inflammation, neoplasms, and obstruction.
Indications/Contraindications: Lacrimal probing and irrigation is indicated in epiphora, trauma, and congenital nasolacrimal duct obstruction. Patients with dacrocystitis or canaliculitis are often not probed and irrigated due to the friability of the infected tissues.
Materials/Methods: A punctal dilator, Bowman probe, 3cc syringe, lacrimal cannula, and normal saline are required for this procedure.
Results: Tactile feedback during lacrimal probing and fluid response during lacrimal irrigation provide insight into nasolacrimal duct anatomic status and help with surgical planning.
Conclusion: Lacrimal probing and irrigation is an effective method of determining the patency of the lacrimal outflow system.
The lacrimal drainage system is responsible for the flow of tears from the medial canthus to the nasal cavity. It consists of the puncta, canaliculi, lacrimal sac, and the nasolacrimal duct. Lacrimal probing and irrigation can be performed whenever analysis of the lacrimal drainage system is warranted. One common indication is investigating excessive tearing (epiphora) that is the result of nasolacrimal obstruction. This can be due to development of an upper system obstruction by edema from infection or dacryolith formation in the canaliculi. However, the more common location of nasolacrimal obstruction is in the lacrimal sac or nasolacrimal duct. Probing and irrigation is effective at not only identifying an obstruction in the system but also identifying the location of the obstruction. Another indication for probing and irrigation is to identify injury to the lacrimal drainage system in the case of trauma to the eyelid or face. If congenital nasolacrimal duct obstruction is unresolved by 12 months, lacrimal probing can be performed to establish patency in the nasolacrimal system. Numerous studies have demonstrated the efficacy of and high patient satisfaction following lacrimal probing and irrigation in the treatment of nasolacrimal duct obstruction1–3.
Preoperative workup: Prior to performing the procedure, a thorough history and complete eye exam with slit lamp biomicroscopy should be performed with a focus on the lacrimal system. The lacrimal puncta should be inspected for size and patency and apposition to globe. The height of the tear lake should also be assessed. Other causes of epiphora should be ruled out, such as dry eye.
Instrumentation/Setup: A punctal dilator, Bowman probe, 3cc syringe, lacrimal cannula, and normal saline are required for this procedure.
Anatomy and landmarks:
The puncta are the entrances to the lacrimal drainage system and are located on the medial margins of the upper and lower eyelids. They open into the superior and inferior ampullae, which are about 1-2mm in vertical height. From the ampullae, the lacrimal system makes a 90 degree turn into the horizontal canaliculi, which run 8-10mm medially. Most people have the superior and inferior horizontal canaliculi meet and form a common canaliculus that enters the lacrimal sac. The valve of Rosenmüller is a membrane which functions as a one-way valve to prevent reflux from the lacrimal sac into the canaliculi. The lacrimal sac extends inferiorly around 10mm and forms the nasolacrimal duct, which runs through the maxilla and is about 12mm in length. The nasolacrimal duct opens into the nose through an ostium in the inferior meatus and contains a distal valve (the valve of Hasner).
A punctal dilator is used to dilate the puncta. The punctal dilator is initially introduced vertically into the punctum and then rotated horizontally. As the dilator is being inserted, lateral traction is applied to the eyelid to straighten the canaliculus and allow passage of the punctal dilator horizontally. The canaliculus is probed with a Bowman probe in a similar fashion until the “hard stop” of the lacrimal bone is felt. A lacrimal cannula attached to a 3mL syringe filled with saline is introduced through the punctum and along the common canaliculus. Gentle pressure is applied to the plunger and the path of irrigant is carefully observed.
A “hard stop” felt during probing of the canaliculi indicates that the probe has contacted the lacrimal bone. This implies that the punctum and canaliculus are patent. A “soft stop” felt during probing can occur in any location along the canaliculus or in the lacrimal sac and indicates stenosis or obstruction. In the setting of acute trauma, a visible lacrimal probe following insertion into the canaliculus or leakage of irrigation fluid through the eyelid indicates canalicular injury.
There are several outcomes of lacrimal drainage system irrigation. In a complete canalicular obstruction, irrigation fluid refluxes from the same canaliculus. In a complete common canalicular obstruction, a “soft stop” is felt at the level of the common canaliculus and irrigation fluid refluxes through the opposite punctum and possibly through the same canaliculus. No fluid will pass through the nose. In a complete nasolacrimal duct obstruction, a “hard stop” is felt and irrigation fluid refluxes through the opposite punctum (often with mucus or pus). No fluid will pass through the nose. In a partial nasolacrimal duct obstruction, fluid will reflux through the opposite punctum as well as through the nose. Finally, if the entire lacrimal drainage system is patent, the cannula will be placed with ease and most of the fluid will pass through the nose with little or no reflux through either punctum. The patient may be able to taste the saline.
Complications of lacrimal probing and irrigation are mainly due to incorrect technique or failure to recognize when to stop advancing the probe and can include creation of a fistula.
Probing and irrigation of the lacrimal system is a common method of assessing its anatomic patency. It requires minimal instrumentation and is a technique that can be quickly learned. It is a critical part of the workup of the tearing patient. Tearing can be a result of lacrimal outflow obstruction but can also be a result of hypersecretion of tears. It is important to distinguish these diagnoses to provide appropriate care for the tearing patient.
Patients who experience epiphora due to hypersecretion of tears often do so because of a diagnosis of dry eye syndrome. The treatment for this includes tear replacement drops, topical medications to increase tear production, or placement of punctal plugs to prolong the presence of tears on the ocular surface.
In patients who are found to have upper lacrimal obstruction (punctal or canalicular obstruction), the treatment is attempted recanalization, often with stent placement. The success rate for this is fairly low and in failed cases the placement of a glass Jones tube may be required.
In patients who are found to have lower lacrimal obstruction (lacrimal sac or nasolacrimal duct), the treatment is a surgery to bypass the obstruction, called a dacryocystorhinostomy (DCR). This can be done externally through the skin or endoscopically through the nose. The success rate for these procedures is quite high (over 90%).
In the case of a traumatic canalicular laceration, treatment is repair with placement of a silicone stent.
1. Guinot-Saera A, Koay P. Efficacy of probing as treatment of epiphora in adults with blocked nasolacrimal ducts. British Journal of Ophthalmology. 1998;82(4):389-391. doi:10.1136/bjo.82.4.389
2. Robb RM. Probing and Irrigation for Congenital Nasolacrimal Duct Obstruction. Archives of Ophthalmology. 1986;104(3):378-379. doi:10.1001/archopht.1986.01050150078031
3. Świerczyńska M, Tobiczyk E, Rodak P, Barchanowska D, Filipek E. Success rates of probing for congenital nasolacrimal duct obstruction at various ages. BMC Ophthalmology. 2020;20(1):403. doi:10.1186/s12886-020-01658-9