Clearing Stagnant Tears: Understanding Lacrimal Lavage

This debris normally clears through the nasolacrimal system. In this article, Dr Leigh Plowman provides a detailed guide for optometrists on lacrimal lavage.

The nasolacrimal system is more than just a drain for debris. A study by Gupta et al. found that 34% of aqueous tear volume was produced by breathing through the nose.¹

Epithelial tissue is continuous between the conjunctiva and upper airway mucosa via the nasolacrimal duct.

The nasolacrimal duct is part of the lacrimal functional unit (LFU) with the ocular surface and includes the cornea, conjunctiva, lacrimal gland, accessory lacrimal glands, meibomian glands, and interconnecting neural reflex arcs.

Therefore, inflammation of the ocular surface may have broader implications on neighbouring structures.

PRIMARY ACQUIRED NASOLACRIMAL DUCT OBSTRUCTION

Primary acquired nasolacrimal duct obstruction (PANDO) occurs where there is complete blockage of the nasolacrimal drainage. It may also be known as ‘toxic soup syndrome’. Patients often present with conjunctival hyperaemia and epiphora.

The pathogenesis of PANDO is unknown. It is thought to have a multifactorial origin and can have a significant impact on activities of daily life.²

RISK FACTORS FOR PANDO

Gouvea et al. recently completed a clinical record review of patients with PANDO. They found that patients often had significant inflammation risk factors. All patients in the study had rosacea or meibomian gland dysfunction. They found that ocular surface inflammation often leads to punctal stenosis.³

Kerber et al. evaluated the risk factors in over 60,000 patients with a history of PANDO.⁴

They hypothesised that PANDO may arise due to descending inflammation (from the ocular surface such as dry eye disease or ocular surface inflammation) or ascending inflammation (from the nose, perhaps from allergies or sinus inflammation). Their study identified several ocular and systemic risk factors for PANDO.

Ocular Risk Factors

• Two or more events of acute conjunctivitis (odds ratio 3.59),
• Chronic conjunctivitis (odds ratio 2.96),
• Vernal keratoconjunctivitis (odds ratio 2.89),
• Blepharitis (odds ratio 2.75), and
• Pterygium (odds ratio 1.88).⁴

Systemic Risk Factors

• Rhinitis (odds ratio 1.62),
• Chronic sinusitis (odds ratio 1.71),
• Deviated nasal septum (odds ratio 1.76),
• Asthma (odds ratio 1.34), and
• Atopic dermatitis (odds ratio 1.36).

PANDO can also cause reduced aqueous tear production on the affected side. A study by Sing et al.⁵ found a significant reduction from normal (0.99 μL/min to 0.8 μL/min). They suggested that there may be “feedback regulation between lacrimal outflow and secretory pathways… between the nasolacrimal duct cavernous body, and lacrimal gland”.⁵

ROLE OF GASTRIC ENZYMES

Gastric enzymes may also affect the nasolacrimal duct and ocular surface. According to De Zazzo et al., gastroesophageal reflux disease (GERD) affects around 44% of the worldwide population. Laryngopharyngeal/ hypopharyngeal reflux (LPR) is the primary manifestation of GERD.⁶

LPR affects the throat, larynx (voice box), and upper airways, leading to throat irritation, and voice issues. Studies have reported that gastric enzymes, such as pepsin, can lodge in the nasolacrimal sac and ocular surface.⁶

Ocular irritation may occur due to the “acidic content of the refluxate”; local inflammation may relate to “pepsin toxicity associated or induced by a neurogenic systemic stimulus”.⁶

In summary, the nasolacrimal sac and duct are critical parts of the lacrimal functional unit. The balance between lacrimal outflow and production is important. Xiao et al. proposed that “the lacrimal apparatus should be considered an integral unit in diagnosing and treating ocular surface diseases”.⁷

NASOLACRIMAL LAVAGE

Nasolacrimal lavage is a simple, underutilised in-office treatment. It takes minutes to perform. Nasolacrimal lavage helps to dilute and clear debris, allergens, biofilms, and reduce inflammation. Nasolacrimal lavage may often help to clear nasolacrimal duct obstruction.

The patients who benefit most from nasolacrimal lavage include those with:

• Chronic ocular surface disease,
• Ocular surface inflammation,
• Sinus congestion,
• Allergies,
• Punctal stenosis,
• Conjunctivochalasis obscuring the lower punctum, and
• Significant gastric reflux (i.e. LPR).

PERFORMING NASOLACRIMAL LAVAGE

Education is the most important step prior to nasolacrimal lavage. Explaining with a diagram of the nasolacrimal system is often helpful. Patients can often relate to the analogy of cleaning out the downpipes on a house.

For most patients, it’s easier to perform lavage via a slit lamp. This makes it easier to visualise the punctum and easier to steady yourself.

If you use a slit lamp, tissues are important to catch saline splashes during the procedure. The metal may corrode if splashes are left on the surfaces for long periods.

Anaesthetic drops normally help the patient to feel comfortable. Reduced blinking helps to maintain the best position and flow of saline into the punctum.

Non-preserved saline can be used. Put saline into a clean contact lens case. Typically, the cases hold around 3 ml of fluid and this amount of saline works for most patients. Multipurpose contact lens solution causes stinging and discomfort in the nasolacrimal system.

Punctal dilators are inexpensive and helpful to probe puncta that appear slightly narrow. Dilators make it easy to assess whether there is any scar tissue obstructing the punctum. In this case, it helps to visualise whether the lacrimal cannula will fit inside the punctum or if the cannula can only fit on the outside surface.

When injecting the saline, maintain constant pressure on the plunger. Ask the patient to let you know when they notice fluid in their nose or throat. Sometimes, you can feel the plunging become significantly easier when the blockage clears.

Ask the patient whether they felt more fluid in one side or another. Often one side will clear easily. The other side may have minimal clearance due to a deviated septum or a fracture or injury in the past (e.g. sport injury or car accident), which may predispose them to reduced flow.

Serial dilution (i.e. multiple lavages) is better than a single nasolacrimal lavage. That is, performing nasolacrimal lavage on each side and then repeating is often helpful. The second round often has a larger volume more quickly. If the volume is small each time, this may indicate stenosis further down. For patients with chronic throat mucous, repeat the lavage and then ask the patient to tip their head back to clear the back of the throat.

WHAT IF IT DOESN’T DRAIN?

For stubborn blockages, it may be helpful to repeat the lavage of the top punctum and bottom. To flush the upper punctum, ask the patient to look down and follow the same technique using the slit lamp. Different angles may help clear mucous or debris.

Patients with a lower punctoplasty often have enlarged puncta. This makes access easy. However, larger punctal size may not seal around the lacrimal cannula. It can be harder to increase fluid pressure (and saline spills out more easily).

For patients that don’t clear well, a repeat nasolacrimal lavage may help in around two weeks. If there is still no flow, referral to an ophthalmologist may be needed to assess the patient and discuss dacryocystorhinostomy.

HOME CARE

Home care is important for patients after successful nasolacrimal lavage. Topical steroids or ciclosporin can be helpful following treatment. These anti-inflammatories help to further reduce inflammation in the lacrimal functional unit. Patients report a significant improvement in symptoms.

Regular saline nasal and sinus rinses (e.g. brands such as Fess) may help reduce ascending inflammation from the nose or sinuses. Patients can use saline rinses once per day in the shower, especially during symptomatic periods.

CONCLUSION

The nasolacrimal sac is a critical part of dry eye disease and ocular surface evaluation. Chronic ocular surface inflammation can cause obstruction of the nasolacrimal duct.

This reduces tear production and leads to toxic tears that perpetuate inflammation. Nasolacrimal lavage is a simple treatment that is helpful for patients with ocular surface disease and chronic inflammation. Patients often appreciate a significant improvement in their quality of life.

Dr Leigh Plowman BOptom (Therapeutics) is an optometrist at Otway Optical in Colac, Victoria. He is the founder of the Dry Eye Directory and frequently writes and presents on dry eye disease.

References

1. Gupta A, Heigle T, Pflugfelder SC, Nasolacrimal stimulation of aqueous tear production. Cornea. 1997 Nov;16(6):645-8. PMID: 9395874.
2. Ali MJ, Etiopathogenesis of primary acquired nasolacrimal duct obstruction (PANDO) Prog Retin Eye Res. 2023 Sep;96:101193. doi: 10.1016/j. preteyeres.2023.101193.
3. Gouvea L, Mimouni M, Chan CC, et al., Clinical features and management of keratoconjunctivitis associated with inadequate tear drainage. Can J Ophthalmol. 2024 Jun;59(3):e206–e212. doi: 10.1016/j.jcjo.2023.03.020.
4. Kerber L, Kerman T, Hazan I, et al., Are inflammationrelated diseases risk factors for primary acquired nasolacrimal duct obstruction? A large scale, national case-control study. Graefes Arch Clin Exp Ophthalmol. 2024 Jun;262(6);1911–1917. doi: 10.1007/s00417- 023-06352-2.
5. Singh S, Srivastav S, Bothra N, et al., Lacrimal gland activity in lacrimal drainage obstruction: Exploring the potential cross-talk between the tear secretion and outflow. Br J Ophthalmol. 2024 Mar;108(4):621–624. doi: 10.1136/ bjo-2022-322577.
6. Di Zazzo A, Micera A, Bonini S, et al., Ocular surface disease as extraesophageal gastroesophageal reflux disease manifestation: A specific therapeutic strategy. 2024 Mar 1;43(3):295–300. doi: 10.1097/ ICO.0000000000003329.
7. Xiao B, Guo D, Liang L, Obstruction of the tear drainage altered lacrimal gland structure and function. Invest Ophthalmol Vis Sci. 2023 Jul 3;64(10):13. doi: 10.1167/ iovs.64.10.13.