Understanding Acquired Tear Duct Blockage (PANDO)

If you are dealing with eyes that seem to “overflow” with tears for no apparent reason, you are not alone. While we often think of tear duct blockages as a problem for babies, many adults develop a condition known as Primary Acquired Nasolacrimal Duct Obstruction (PANDO) ^[1][2].

PANDO is a common reason for persistent tearing in adults. It can be frustrating and socially embarrassing to constantly dab at your eyes, but understanding the biology of why this happens is the first step toward finding a solution.

What is PANDO?

Unlike congenital blockages that infants are born with, PANDO is an acquired condition that develops over time ^[2]. It occurs when the nasolacrimal duct—the channel that carries tears from your eye into your nose—becomes narrowed or blocked.

PANDO is a multifactorial condition that is thought to involve chronic, low-grade inflammation ^[1]. Think of this like a slow-moving irritation in the lining of the duct. Over time, this inflammation is frequently associated with fibrosis, which is the formation of scar tissue ^[1][3]. As this scar tissue builds up, the duct loses its flexibility and the opening becomes smaller and smaller, eventually preventing tears from draining away ^[1].

Who is Affected?

PANDO primarily affects adults, and it is significantly more common in women than in men ^[4][2].

• Hormonal Links: Research suggests that hormonal changes, particularly those occurring after menopause, may play a role in the health of the tear duct lining ^[5].
• Anatomy: Some studies have looked at whether women have naturally narrower tear duct channels in the bone, though current evidence suggests that while a narrow canal might be a “predisposition,” it isn’t the sole cause of the blockage ^[4][5].

Primary Symptoms: More Than Just Watery Eyes

The most common symptoms of PANDO are epiphora (constant tearing) and discharge ^[6].

1. Epiphora: This is the medical term for tears overflowing onto the cheek. Because the drain is clogged, the natural tears your eye produces have nowhere to go but out. This can cause blurred vision and skin irritation around the eye ^[6].
2. Discharge: You may notice a sticky or mucus-like substance in the corner of your eye. This happens because the stagnant fluid trapped in the tear sac can become thick ^[6][2].

Not All Tearing is PANDO
It is important to know that epiphora has multiple causes. It can also result from dry-eye reflex tearing, allergy, eyelid malposition, punctal narrowing, medication effects, and functional pump problems. Therefore, readers should not equate watery eyes automatically with PANDO.

The ROPLAS Sign: A Clinical Test

One of the reliable ways clinicians check for a blockage in the lower part of the tear duct is a maneuver called ROPLAS (Regurgitation on Pressure over the Lacrimal Sac) ^[7].

• How it works: A doctor applies gentle pressure to the lacrimal sac, located in the corner of the eye next to the bridge of the nose.
• What it means: If pressing on this area causes fluid, mucus, or pus to “reflux” or push back out through the tiny openings in your eyelids (the puncta), it is a strong sign that the duct is obstructed further down ^[7].

Interestingly, if you notice this spontaneous reflux yourself and report it to your doctor, limited studies show it can be a strong indicator ^[7]. Important Safety Warning: You should never press or manipulate your own lacrimal sac, especially if it is painful, red, or swollen, as this requires careful clinical assessment. While a positive ROPLAS test supports an obstruction, a negative result doesn’t always mean the duct is clear—it might just mean the blockage is only partial (stenosis) or located in a different spot ^[7][8].

Validating Your Experience

Living with PANDO is more than a minor nuisance. Constant tearing can make it difficult to read, drive, or apply makeup. It can also lead to social anxiety, as it often looks like you are crying when you are not. It is important to know that this is a recognized medical condition with a biological process of inflammation and scarring ^[1][3].

Your care team will use various tools—such as irrigation (flushing the duct with saline) or specialized imaging like dacryocystography (a type of X-ray using dye)—to confirm the exact location of the blockage and help you decide on the best way to restore clear vision and comfort ^[8][9].