Lacrimal irrigation test (Lacrimal Irrigation Test)

Key points of this condition

• The lacrimal irrigation test (lacrimal syringing) is a basic functional test that injects saline through the punctum with a lacrimal irrigation needle to assess blockage in the lacrimal drainage system
• The main indications are epiphora, chronic eye discharge, recurrent conjunctivitis, keratitis, and suspected dacryocystitis, and it can be performed immediately in the outpatient clinic
• After topical anesthesia with 0.4% oxybuprocaine eye drops, the procedure is performed with a curved lacrimal irrigation needle (about 8 mm from the tip to the bend) and a 2.5 mL syringe
• The results are classified into five patterns: ‘good irrigation’, ‘distal common canalicular obstruction’, ‘canalicular obstruction’, ‘dacryocystitis associated’, and ‘lacrimal sac/nasolacrimal duct obstruction’
• The concordance rate between the obstruction site estimated by irrigation testing and lacrimal endoscopic findings is around 70%¹⁾, and endoscopic examination may be needed for a definitive diagnosis
• In congenital nasolacrimal duct obstruction, irrigation testing is used to decide whether to move on to lacrimal sac massage and probing²⁾
• In patients using anticancer drugs such as TS-1, caution is needed for the risk of progression of lacrimal duct obstruction, and if resistance is strong, a lacrimal tube should be placed early

1. What is lacrimal irrigation testing

Lacrimal irrigation test (lacrimal irrigation test / lacrimal syringing) is a functional test in which saline is injected from the punctum with a syringe attached to a lacrimal irrigation needle to infer whether there is a passage obstruction and the site of obstruction in the lacrimal drainage system. By observing whether the solution flows into the nasal cavity and pharynx (the patient’s sensation), whether there is reflux from the punctum, and the character of the reflux fluid (serous or purulent), the presence and site of obstruction are assessed.

After topical anesthesia, inserting while keeping the anatomy of the vertical and horizontal parts of the canaliculus in mind leads to a more accurate assessment. The procedure is simple and widely used as an outpatient procedure, and it is regarded as an essential test in the initial evaluation of patients who complain of epiphora and eye discharge.

Indications

Lacrimal irrigation is actively performed in the following situations. Because lacrimal duct obstruction is often hidden behind recurrent conjunctivitis and keratitis, it is recommended to perform it proactively in routine practice to avoid missing it.

• Epiphora — the most common chief complaint
• Chronic or recurrent eye discharge
• Recurrent conjunctivitis or keratitis (to rule out lacrimal duct obstruction)
• Suspected dacryocystitis (swelling over the lacrimal sac and redness at the inner corner of the eye)
• Confirmation of patency after removal of a lacrimal tube

Q In what symptoms is lacrimal irrigation performed?

A

It is performed in patients with epiphora (tearing), chronic eye discharge (eye mucus), and recurrent conjunctivitis or keratitis. If lacrimal duct obstruction is missed, it can cause chronic infection, so it is important to actively perform the test in these symptoms. It is also used to confirm patency after removal of a lacrimal tube.

2. Pre-examination checks

Checking medication use history

The following medications can cause lacrimal duct disorders and must be checked before the examination.

• Fluoropyrimidine anticancer drugs, including TS-1 (tegafur/gimeracil/oteracil potassium): they can cause lacrimal duct obstruction. If the blockage progresses, treatment becomes difficult, so if you feel strong resistance when inserting the irrigation cannula, place a lacrimal tube early to help prevent the obstruction from worsening.
• Rebamipide eye drops (rebamipide): used for dry eye, but they can harden inside the lacrimal drainage system and cause dacryolithiasis.

Confirm anterior segment findings

Evaluate the following before irrigation testing.

• Tear fluid characteristics: serous and clear is normal. Viscous or purulent fluid suggests dacryocystitis or lacrimal duct obstruction.
• Krehbiel flow: observe with a slit-lamp microscope how the tear fluid flows from the punctum into the canaliculus after blinking. If the lacrimal drainage system is obstructed, absorption does not occur.
• Punctal morphology: punctal stenosis or obstruction can be caused by infection, chronic conjunctivitis, allergy, after cataract surgery, or glaucoma eye drops.
• Canaliculitis: this is especially easy to miss, and should be actively suspected if discharge is seen when the punctum is pressed.
• Dry eye, conjunctivochalasis, and eyelid abnormalities: check these to differentiate them from reflex tearing or impaired tear drainage.

3. Examination procedure (position, instruments, technique)

Lacrimal irrigation test: a procedure in which a cannula is inserted into the lower punctum and saline is injected.

Stevens S. Lacrimal syringing. Community Eye Health. 2009;22(70):31. Figure 4. PMCID: PMC2760283. License: CC BY.

With the eyelid pulled outward, a cannula is inserted into the lower punctum and saline is injected under pressure with a syringe. This shows the step of inserting the irrigation cannula into the punctum and the pressurized injection technique described in the section “Examination procedure (position, instruments, technique)”.

Positioning and setup

Place the patient supine on the procedure bed. Supine positioning stabilizes the head, makes the procedure easier, and allows easier observation. Placing cut cotton on the skin outside the treated eye is convenient because it saves the trouble of repeatedly wiping away any irrigation fluid that flows back.

Having staff prepare the following in advance can shorten the procedure time:

• Placing cut cotton pads
• Topical anesthesia with 0.4% oxybuprocaine eye drops (this is sufficient in many cases)

Choosing the lacrimal irrigation needle

Type	Features	Recommendation
Straight type	Can be inserted as far as the nasolacrimal duct	Preferably avoided by anyone other than experienced operators (risk of blind insertion)
Curved type	About 8 mm from the tip to the bend	Recommended for routine cases

Irrigation fluid is often normal saline. If a mixture with povidone-iodine (16-fold dilution) is used, an added antiseptic effect can be expected. A 2.5 mL syringe is easier to handle and lets you sense resistance more clearly (compared with 5 mL).

Tips for the procedure (numbered steps)

1. Identification of the punctum: Check the upper and lower puncta; usually perform the procedure from the lower punctum
2. Lid retraction: With the hand opposite the syringe, firmly pull the eyelid outward to straighten the canaliculus. If you advance the needle before it is fully straightened, the tip may touch the side wall of the canaliculus and be mistaken for blockage
3. Insertion of the irrigation needle: The canaliculus runs vertically for about 2 mm from the punctum, then curves at nearly a right angle toward the lacrimal sac. Insert the irrigation needle with this anatomy in mind
4. Advance to the bend: With a curved-type irrigation needle, advance it to the bend from the tip (about 8 mm) so that it reaches the common canaliculus just before the lacrimal sac
5. Pressurize and assess: Gradually increase pressure as you push the syringe. Assess whether there is resistance, whether there is reflux and from which punctum the reflux occurs (same side or opposite side), and the nature of the refluxed fluid (serous or purulent)
6. Confirm with the patient: Confirm whether the patient felt the irrigating fluid flow into the nasal cavity or pharynx

Q Is lacrimal irrigation painful?

A

Because topical anesthesia with 0.4% oxybuprocaine eye drops is used, discomfort during the procedure is minimal in most cases. You may feel a slight sense of pressure when the lacrimal irrigation needle is inserted, but severe pain usually does not occur. It is important to provide enough topical anesthesia before the examination.

4. Interpretation of Results

Based on the irrigation findings, the site of obstruction is estimated in the following five patterns.

Findings	Interpretation
Flow into the nasal cavity and pharynx (noticed by the patient)	Good irrigation flow (normal)
No resistance; reflux from the same-side punctum	Communication between the upper and lower lacrimal passages; obstruction distal to the common canaliculus (lacrimal sac or nasolacrimal duct)
Strong resistance; reflux from the same-side punctum	Obstruction of the canaliculus or common canaliculus
Purulent reflux fluid	Nasolacrimal duct obstruction with dacryocystitis (chronic dacryocystitis)
Regurgitation from the opposite punctum	Lacrimal sac/nasolacrimal duct obstruction; upper and lower canaliculi patent

The probability that the estimated obstruction site from irrigation testing matches the actual findings during lacrimal endoscopic surgery is around 70%, so it is by no means high¹⁾. For a definitive diagnosis of the obstruction site, lacrimal endoscopy may be necessary.

Limitations of irrigation testing

Irrigation testing is simple, but the accuracy of estimating the obstruction site has only about a 70% match with lacrimal endoscopic findings¹⁾. Even if there is strong resistance or regurgitation, keep in mind the possibility of a false positive due to the way the needle is advanced (for example, poor canalicular straightening because of insufficient lid traction).

5. Auxiliary tests

Dye retention test

A useful adjunctive test when lacrimal irrigation is difficult because body movement cannot be controlled, such as in children.

• Fifteen minutes after fluorescein staining, assess whether fluorescent dye remains in the conjunctival sac or flows onto the eyelids
• Its sensitivity for congenital nasolacrimal duct obstruction is said to be about 95%
• In adults, it can also be used to diagnose functional epiphora when combined with irrigation testing

Micro-Reflux test

A diagnostic adjunct used when dacryocystitis is suspected. If pus refluxes when the lacrimal sac area is pressed, dacryocystitis can be diagnosed. It is also a method for simultaneously diagnosing lacrimal duct obstruction using fluorescein dye.

Dacryocystography

After confirming obstruction with an irrigation test, it is used for a detailed anatomical assessment of the site of obstruction. It combines contrast injection and imaging, but it can sometimes be difficult to determine where the contrast has reached, and it may be combined with lacrimal endoscopy¹⁾.

6. Role of lacrimal irrigation in congenital nasolacrimal duct obstruction

Congenital nasolacrimal duct obstruction is the most common cause of tearing and eye discharge in infants, and the irrigation test is used to decide whether to move from conservative treatment to surgery²⁾.

The recommendations in the congenital nasolacrimal duct obstruction treatment guideline²⁾ are as follows.

• CQ1 Lacrimal sac massage (Crigler method): Weakly recommend performing it. It is done with the aim of opening the obstructing membrane at the lower end of the nasolacrimal duct by increasing pressure
• CQ2 Topical antibiotics: Weakly recommend using them only when necessary. Use them only when signs of infection such as eye discharge or conjunctival redness are present
• CQ3 Surgical intervention (probing): In unilateral congenital nasolacrimal duct obstruction, probing under local anesthesia around 6 to 9 months of age is weakly recommended. Because the spontaneous resolution rate within the first year is high, observation until then is the rule
• Repeat probing after initial probing failure: Weakly recommend against it. In failed cases, consider lacrimal tube insertion under lacrimal endoscopy

The irrigation test is used to confirm obstruction and to decide whether surgery is appropriate between 6 and 15 months of age.

Q Does congenital nasolacrimal duct obstruction require surgery?

A

About 90% are said to resolve on their own within the first year of life, so conservative treatment (lacrimal sac massage and antibiotic eye drops) is tried first. If it is on one side and there is no improvement after 6 to 9 months of age, probing under local anesthesia is chosen. For cases on both sides or complex cases, endoscopic lacrimal surgery under general anesthesia is considered²⁾.

7. Management of special cases

Lacrimal irrigation for bacterial clearance (palliative treatment)

For nasolacrimal duct obstruction with dacryocystitis, radical treatment such as lacrimal tube insertion or dacryocystorhinostomy (DCR) is appropriate. However, when surgery is difficult (poor general condition, patient refusal, etc.), palliative drainage may be done by regular lacrimal irrigation. It is important to repeat irrigation until the refluxed irrigating fluid becomes clear. A method of instilling antibiotic eye ointment into the lacrimal passage after irrigation is also used.

Anticancer drug-related lacrimal duct obstruction

Fluoropyrimidine anticancer drugs, including TS-1 (tegafur, gimeracil, and oteracil potassium), are known to cause lacrimal duct obstruction. If there is strong resistance when inserting the lacrimal irrigation needle, early placement of a lacrimal tube can help prevent progression of the obstruction. In patients receiving TS-1, regular lacrimal irrigation and monitoring are desirable.

Dacryolithiasis associated with Levamid eye drops

Levamid sodium (Levamid) eye drops, used for dry eye, can solidify within the lacrimal passages and cause dacryolithiasis. In patients using Levamid eye drops who complain of tearing and eye discharge, perform lacrimal irrigation with the possibility of dacryoliths in mind. If strong resistance is felt, confirmation with lacrimal endoscopy is useful.

Evaluation after removal of the lacrimal tube

Perform lacrimal irrigation before and after removal of the lacrimal tube placed after surgery to confirm patency. Because some cases develop re-obstruction after removal, regular lacrimal irrigation during the 1 to 3 months of follow-up after removal is recommended.

8. References

1. 日本涙道・涙液学会涙道内視鏡診療の手引き作成委員会. 涙道内視鏡診療の手引き. 日本眼科学会雑誌. 2023;127(10):896-917.
2. 先天鼻涙管閉塞診療ガイドライン作成委員会. 先天鼻涙管閉塞診療ガイドライン. 日本眼科学会雑誌. 2022;126(11):991-1021.