What's it all about?
The eyes have four drains, called puncta, through which tears (which are constantly renewed) exit. These are in the lower and upper corners of the eyelids nearest the nose.
For patients whose dry eye symptoms are caused primarily by a deficiency in the water (aqueous) part of their tears, stopping the drains (called punctal occlusion) can sometimes help improve the symptoms. There are two ways to do this: using small plugs, or permanently sealing the openings with cautery. Plugs are far and away the most common of the two treatments. These include temporary collagen plugs, which dissolve by themselves, which can be placed in order to test the likelihood that silicone plugs or cautery will be helpful and will not result in tear overflow (epiphora).
What is a punctum and what are punctum plugs? (Where are punctum plugs placed in the eye?)
Puncta are the drainage ducts that your old tears, or extra tears, can escape through while your glands are making new ones. In each of your eyes, there is one punctum in the top eyelid and another on the bottom eyelid, at the corner of the eye that is towards your nose.
Punctal plugs do exactly what they sound like: They stop the drains, just like the plug in your kitchen sink. They are not quite as easy to put in as the plug in your sink, and they are definitely not as easy to get out (at least, not the kind that go right now into the canalicula).
Why might I get collagen plugs first?
Collagen plugs dissolve on their own, usually within a few days of insertion. They are a useful way to determine whether you might be a good candidate for permanent punctal plugs.
Some patients will experience tear overflow (epiphora) with punctal plugs. If they go straight to silicone plugs, then depending what type they get it may be difficult to remove them. Collagen plugs will not necessarily prove whether silicone plugs will be helpful, but they can help gauge patients who will have overflow or who simply are very unlikely to benefit.
What is it like to get plugs? Does it hurt?
Punctal plugs are sold with a long tweezer-y looking thing used to insert them. Now, how they are inserted depends partly on what kind of plug they are, for example, some fit right into the top of the punctum (and you can see the caps in the mirror) while others are shoved way down into the canaliculum. But broadly speaking, here is what will happen: Your eye doctor will put in some eyedrops to anaesthetise your eyes. He’ll then use one part of the tweezer-y thing to poke into the puntum and stretch it out a bit. Once it’s ready, he uses the other part of the thing to push the plug into the punctum. Plunk! It’s there. On to the next punctum.
In some cases your eye doctor may have to wrestle with your punctum a little bit to get the plug in. It really shouldn’t hurt at all, but you know, that’s what they told me about my wisdom teeth before the five shots of novocaine and the footprint my dentist left on my face when he braced himself and pulled. If your eye doctor hasn’t done this very often, as was the case with me once, it might be a little uncomfortable, but that's unusual. Really. You should be just fiiiiine.
If you hadn’t already figured this out, the fact is that every time I’ve had plugs put in, it was not my favourite experience, but to be honest I think the anticipation is worse than the fact. My best experience with plug insertion was SmartPlugs, because with those ones they don’t have to stretch open the puncta the way they do with standard plugs. Didn’t feel a thing.
What happens once the plugs are in?
After the anaesthetic wears off, you may be sore from the insertion process. Some people also have a reaction to the plugs that makes them feel uncomfortable - this may even last up to a few days. If this happens to you, please don't despair, don't claw at your eyes and unless it's intolerable don't force your eye doctor to remove them - chances are, the discomfort will pass and in a couple of days you'll feel much better. On the other hand, if you see swelling or have constant pain, by all means call your doctor.
A minority may find that their tears pool up and run over after the plugs are in. There's even a fancy term for it — epiphora. (Now you can really impress your doctor by asking about epiphora before he even puts the plugs in, rather than give him the satisfaction of explaining it to you after you get it.) Personally, I have never had epiphora from plugs, but I know people who did or do. Some people experience significant enough benefits from the plugs that they tolerate the overflow as the price they pay for healthier and/or more comfortable eyes. Too much overflow can be either embarrassing or convenient, depending whether it’s happening during a job interview or while your great aunt is telling you all about her latest hospitalisation. But chronic overflow may be unhealthy as well as inconvenient, so by all means keep your doctor up to date on what's going on.
For more about the wonderful world of plugs, refer to our plug page and to the plugs forum on Dry Eye Talk.