Air trapping in the lacrimal sac is medically known as a lacrimal sac pneumatocele, occurring when air enters the tear drainage system. The lacrimal sac is a small reservoir situated near the inner corner of the eye, adjacent to the bridge of the nose, designed to collect tears before they drain away. This is a relatively uncommon occurrence that is often benign. A soft, compressible swelling in the area of the tear sac signals that air has become lodged in this pathway.
Understanding the Lacrimal Drainage System
The lacrimal drainage system guides tears from the eye surface into the nasal cavity. Tears enter two tiny openings, called puncta, located on the upper and lower eyelids near the nose. From the puncta, tears flow through small tubes known as canaliculi, which deliver the tears into the lacrimal sac.
The lacrimal sac is the upper portion of the nasolacrimal duct, a bony channel that directs fluid downward into the nasal cavity’s inferior meatus. A membranous fold, called the Valve of Hasner, guards the opening into the nose. This valve acts as a one-way barrier, preventing the backflow of material, including air, from the nose into the tear system.
The continuous connection between the tear system and the nasal cavity allows for the potential backflow of air. While tears normally flow only toward the nose, a significant increase in nasal cavity pressure can overwhelm the one-way mechanism. This forces air to travel retrogradely up the nasolacrimal duct and into the lacrimal sac.
Common Reasons Air Becomes Trapped
Air becomes trapped primarily due to a sudden rise in pressure within the nasal passages. This pressure increase is generated by performing a Valsalva-like maneuver, such as forceful nose blowing when the nostrils are blocked. Aggressive sneezing while attempting to keep the mouth and nose closed can also create enough positive pressure to overcome the natural valve.
This mechanism is more likely if the Valve of Hasner is naturally weak, absent, or disrupted. The resulting air-filled sac, or pneumatocele, may expand and collapse visibly with movements that affect intranasal pressure.
Another cause relates to previous medical procedures that alter the tear drainage system anatomy. Patients who have undergone dacryocystorhinostomy (DCR) surgery, which creates a new drainage channel to bypass a blockage, may experience air reflux. Since DCR intentionally bypasses the natural valve, elevated nasal pressure can push air directly into the new pathway. Nasal trauma involving the bony structure surrounding the nasolacrimal duct can also allow for air trapping.
Safe Techniques for Releasing Trapped Air
The goal of releasing trapped air is to reverse the pressure differential without causing damage to surrounding structures. The most common self-management technique involves applying gentle, directed pressure to the lacrimal sac area. Place a clean finger or cotton swab at the inner corner of the eye, right next to the nose.
Apply light, consistent pressure, directing the movement downward and slightly toward the nose. This motion mimics natural tear drainage and encourages the trapped air to move down the nasolacrimal duct into the nasal cavity. Repeat this process several times, ensuring the pressure remains gentle to avoid pain or bruising.
Avoid any actions that increase pressure in the nasal cavity while attempting to release the air. Refrain from forceful nose blowing, suppressing sneezes, or other straining maneuvers. If a sneeze is unavoidable, release it through an open mouth to minimize pressure transmitted to the nasolacrimal duct.
Applying a warm compress to the affected area may be beneficial as supportive care. The heat can help relax surrounding tissues and potentially reduce minor swelling or discomfort associated with the pneumatocele. If the air is not easily released, avoid aggressive or repeated forceful compression, as this can lead to irritation or injury.
Indicators for Seeking Professional Help
While a lacrimal sac pneumatocele often resolves with gentle self-management, certain signs indicate the need for prompt medical attention. Consult a healthcare professional, typically an ophthalmologist or ENT specialist, if the air bubble persists for more than 24 to 48 hours without reduction in size. Persistence may suggest a complicated underlying issue or an anatomical structure preventing air escape.
Immediate medical evaluation is necessary if the trapped air is accompanied by symptoms of dacryocystitis, which is an infection. These signs include significant pain, marked redness, or firm, tender swelling over the lacrimal sac area. The presence of a fever or the discharge of pus or thick mucus from the puncta or the eye also indicates a developing infection requiring antibiotic treatment.
Any change in vision, even if minor, warrants an urgent examination by an eye doctor.