What about Punctal Plugs (or - “Why not dam up those tears”)?
As a dry eye specialist, I often get asked about using punctal plugs for dry eye disease control. I find that the answer to that very good question is the common “it depends” - in that those with good-quality tears but poor-quantity can do well with plugs in general - but poor-quality tears generally do not.
“Punctal plugs” are anything that can block the flow of tears from reaching the usual destination involving normal, tiny openings along the inner portion of upper and lower lids, that carry tears through a drainage system that ends up in the back of the nose, leading to the back of the throat. They intentionally block this natural system, where the old, used-up tear on the surface of the eye can be blinked away and down the throat, while the new, fresh tear comes up from the little “tear gutter” (called the fornix, it is the reservoir behind the lower lid) to replace the used-up tear. If a blink is the “heartbeat” of the eye, then this turnover is the “circulatory system.”. Retaining more tear volume can work wonders for some and be problematic for others. These plugs come in many forms and sizes to accommodate the anatomic variety we see among our dry eye patients. This Mayo Clinic link provides a quick overview and diagram: https://www.mayoclinic.org/diseases-conditions/dry-eyes/multimedia/punctal-plugs/img-20007894#:~:text=One%20approach%20to%20treating%20dry,tears%20you%20may%20have%20added.
Once the common causes of inflammation have been dealt with (see my earlier posts on inflammation) - if ATD prevails, then plugs can be an eye saver (but should be periodically checked, with good lid hygiene and often replaced - to keep them from accumulating biofilm and the germs it carries – see below and my earlier posts on lid hygiene).
Treating patients, my first goal is to determine the root cause(s) of the patient’s dry eye disease. If primarily MGD (Meibomian Gland Dysfunction – where malfunctioning oil producing glands are causing dry eye disease – see my earlier posts on this), then plugs tend to be less helpful and may make things worse (more on this in a moment). ATD (Aqueous Tear Deficiency, where the “Sprinkler System” makes too little water) means the tear volume is too low (since most tear volume is made from water) and is a more common target for punctal plugging, which will retain more of that tear on the surface of the eye. Unfortunately, many dry eye patients have a mix of MGD and ATD. Poor oil will cause rapid evaporation and lead to “dry spots,” which often requires the “Fire Hose” glands to kick in, causing what we call “Reflex Tearing.” This flood leads to overflow, which can make tears run down the face even with the normal, full function of the tear drainage system. The overflow can get much worse when the system is blocked off by these plugs if reflex tearing continues after the plugs are put in.
A common cause of ATD is inflammation. If there’s a lot of inflammation, then plugs generally make it worse, as this is a “poor quality tear” that - thanks to plugging - doesn’t leave, and perpetuates the dry eye problem by leading to higher levels of inflammation. I’ve heard this referred to as “leaving the dirty bathwater in the tub and expecting it to make you clean.”
If most oil and inflammation issues are reasonably controlled and the tear volume is the remaining, primary problem, then plugs can be a great help. The types of plugging available boils down to:
- Exposed plastic (usually silicone-derived) plugs inserted directly into the “mouth” of the openings along the lid (called the punctum), which have a form of inverted umbrella design to ensure they stay in place as an anchor. The small, “contact lens-like cover” functions as an “end cap” that is visible microscopically, but rarely to the naked eye.
- “Permanent” plugs made from, small, tubular forms of plastic designed to swell inside the tiny tubes or channels that connect the punctum to the nose. These are inserted through the punctum and are carried along the channel until the swelling - or a bend in the channel - “catches” the plug and traps further flow. They are invisible but not always permanent, as they may wash through the drainage system before they “grab” and fix to the lining of the channel.
- “Temporary” plugs made from dissolvable materials designed to swell inside the tiny tubes or channels that connect the punctum to the nose. These are inserted through the punctum and are carried along the channel until the swelling - or a bend in the channel - “catches” the plug and traps further flow, but then gradually “dissolves” and re-establishes flow. The rate of dissolving is a function of the materials used to make these plugs and the amount of irritation they may cause, which can provoke faster dissolution and may lead to scarring within the channels. Like the “permanent” internal plugs, they are also invisible and can also wash through the drainage system before fixing to the wall of the channel.
- Cautery - a small burn over the mouth of the punctum, causing a scar to act as the plug. The lid is numbed before the heat is applied, so this is typically a near-painless procedure. Punctal cautery is a more “complete” plug, in that plastic plugs typically allow a little “wicking” of tears around the plug, so there can still be a little clearance.
Since tears are best when “fresh” and since plugs and cautery encourage degrees of stagnation, there are patients who get less complete benefits. Also, though tiny, exposed plugs are plastic and can be viewed as smaller “contact lenses.” That said, they, like contacts, can accumulate “plaque” (like the grunge that accumulates on teeth and acts as footing for more germs), so changing out plugs periodically (& doing good lid hygiene) is generally required. Reflex tearing is common in dry eye patients and once the plugs block drainage, the only route “out” is by evaporation, the wicking around a plug or over the lid crying, so if you puddle up in a dry wind, then consider this as a likely side effect. Seasonally the benefit of plugs depends - as those with allergies may suffer more by keeping allergens like pollen in - but drier weather like in air conditioning or winter, may be better “fits” for the plugs as dry air means more evaporative loss (as long as the occasional reflex tearing is not too great of a nuisance).
With exposed, plastic plugs, it is usually easy to remove them if problematic (not so easy if cauterized). Plugs retained along the internal channels may be forcibly flushed in a way that can propel them through the system and into the nose. Obviously, cautery means no plastic materials are involved (but also may mean more stagnation), so there’s nothing to fall out or change. Cautery should be regarded as “permanent,” although the scar will sometimes “heal open” or – in cases where the reflex tearing is problematic, may be able to be operated on to re-open (though that can be difficult or impossible in some cases). Rarely, exposed, plastic plugs can trigger scar formation that can cover over or expel the plugs and removal can be problematic, as older plugs can become more fragile and break off, leaving retained pieces inside the lower opening (which may then require a small operation to retrieve).
I've generally shied away from the dissolvable or disappearing plugs as it is hard to know when they are gone (either dissolved or having been swept away and down the tear duct into the nose or mouth). Sometimes these “internal” plugs will trap just enough stagnant tear within the channel as to provide a happy “culture medium” for germs to thrive in – and infections from these kinds of plugs can be hard to treat as this may lead to an internal abscess that then requires surgical drainage to fix.
Common dry eye treatments like lid cleaning, heated expressions and IPL are not overly likely to displace the average plug. If it falls out or dissolves, it can be easily replaced - so whether that happens from a Blephex, Lipiflow or other manipulation, I don't see that as too bad (other than cost) as it is not a bad idea to replace plugs every so often anyway (as I mentioned that they can become breeding grounds for bacteria or other grunge). As a provider of BlephEx, IPL and various heated expressions of MGD, I've not let plugs stop me from recommending that treatment if it is indicated. Fortunately, Punctal Plugs are usually covered by most insurance, are quick and generally painless to place, equally easy to remove (if exposed) and replace when indicated. Check with your dry eye specialist to see if they may be right for you.