Punctal stenosis describes a condition where the tiny openings in the eyelids, known as puncta, become narrowed or completely closed. These openings are the entry point for the eye’s tear drainage system, and their blockage prevents tears from leaving the eye efficiently. This failure in tear clearance results in chronic watery eyes and is a frequently encountered cause of excessive tearing. Punctal stenosis is usually an acquired condition, often seen in older adults, and the resulting poor drainage can cause significant discomfort.
Understanding the Lacrimal System and Puncta Function
The lacrimal apparatus is the biological system responsible for producing and draining tears from the eye’s surface. Tears are constantly produced by the lacrimal glands, located behind the upper eyelid, and are essential for maintaining a healthy ocular surface. After washing over the eye, tears collect in a small pool, called the tear meniscus, along the margin of the lower eyelid closest to the nose.
Tears enter the drainage pathway through the lacrimal puncta, small openings situated on the inner corner of both the upper and lower eyelids. Each punctum leads into a small tube called a canaliculus, which carries tears into the lacrimal sac. From the lacrimal sac, the tears travel down the nasolacrimal duct and empty into the nasal cavity, explaining why crying often causes a runny nose.
The act of blinking helps pump tears into the puncta and down the drainage system. When the eyelids close, surrounding muscles contract, creating a suction force that actively draws tears from the eye surface. When punctal stenosis occurs, this first step of tear drainage is compromised, causing the entire system to back up and overflow.
Identifying the Symptoms of Blockage
The most common symptom of punctal stenosis is epiphora, the medical term for persistent, excessive watering or tearing. This occurs because the narrowed punctum cannot drain tears at the rate they are produced, causing them to spill over the eyelid margin and onto the cheek. The constant moisture can lead to secondary issues affecting comfort and vision.
Overflowing tears can blur vision, making tasks like reading or driving difficult, and require frequent wiping. The skin around the eye, particularly the lower eyelid, can become chronically moist, leading to irritation, redness, and maceration. This constant wetness also raises the risk of recurrent eye infections, such as conjunctivitis, because stagnant tears provide a breeding ground for bacteria.
Symptoms often worsen in environmental conditions like cold temperatures, wind, or bright light, as these factors stimulate a reflex increase in tear volume. The compromised drainage system is then overwhelmed by the sudden increase in fluid. During examination, a doctor may observe an elevated tear meniscus height, which is a sign of poor drainage.
Common Causes of Narrowing
Punctal stenosis is overwhelmingly an acquired condition, developing over time rather than being present from birth. A significant contributing factor is the natural aging process, often called involutional change. As individuals age, the tissues around the punctum can become more fibrous, causing the opening to gradually narrow.
Chronic inflammation of the eyelid margin is a major cause, with chronic blepharitis being the most common predisposing factor. Persistent irritation can lead to scarring and fibrosis of the punctal opening, restricting tear flow. Eyelid infections, such as those caused by the herpes simplex virus or trachoma, can also result in scarring and subsequent stenosis.
Exposure to certain medications can also induce punctal narrowing. Systemic chemotherapy drugs, such as 5-fluorouracil, docetaxel, and paclitaxel, are known culprits due to their toxic effects on cells lining the lacrimal system. Long-term use of certain topical eye drops, particularly anti-glaucoma medications like timolol or latanoprost, has also been associated with the development of stenosis.
Treatment Options for Restoration
The goal of treating punctal stenosis is to physically widen the narrowed opening and restore the natural tear drainage pathway. Initial treatment may involve simple punctal dilation, where a fine instrument is used to stretch the punctum under local anesthesia. This less invasive approach is often temporary, as the opening may narrow again, necessitating a more permanent solution.
The definitive procedure for acquired punctal stenosis is punctoplasty, a minor surgery designed to permanently enlarge the opening. Techniques like “one-snip” or “two-snip” procedures involve making a precise incision into the punctum and the wall of the canaliculus. The goal is to reshape the tissue to create a wider, stable opening that remains patent and functional.
Punctoplasty is often combined with the temporary placement of a silicone stent or tube. This tube, known as an intubation set, is threaded through the newly opened punctum into the drainage system. The stent acts as a scaffold to keep the punctum and canaliculus open while the tissue heals, preventing the recurrence of narrowing. The tube is typically left in place for several weeks to months and is then easily removed in the office.