Punctal plugs are very small, biocompatible devices that get inserted into the tear ducts for blocking drainage. They increase the surface moisture and tear film in the eyes to provide relief for dry eyes.
These devices are also called occluders, lacrimal plugs or punctal plugs, and are no bigger than a single grain of rice.
Usually, punctal plugs are considered whenever prescription or non-prescription eye drops do not provide relief for a dry eye condition.
There are two general kinds of tear duct plugs:
- Semi-permanent: These tend to be made out of long-lasting materials like silicone.
- Dissolvable: These are made out of materials like collagen that are eventually absorbed by the body.
Dissolvable or temporary punctual plugs normally will last from a couple of days up to several months. Those kinds of plugs are used in situations like to prevent dry eyes following LASIK if you decide to get refractive surgery.
Temporary, dissolvable punctal plugs are sometimes used to determine whether the treatment will work on the dry eye condition that you have. If it does, then you might be able to consider semi-permanent punctal plugs.
How Do Punctal Plugs Get Inserted Into The Tear Ducts?
Your eye doctor may first use a special instrument for measuring how large your tear duct openings are (puncta), depending on the kind of punctal plug you have chosen. It will help to determine the right size punctal plug that is needed for blocking drainage in the change and for keeping it in place securely.
There are many eye doctors that only need a close-up, light exam of your eye to determine the type and size of punctal plug that is needed. A one-size-fit-all type of punctal plug might be used in some cases.
To get you prepared for this procedure, a local anesthetic will be used by some eye doctors before the punctal plug is inserted. No anesthetic will be needed in many cases.
There is one punctum on each eyelid, that is located on the inner margin close to the nose. It is possible to insert a punctal plug into the puncta of the upper lids, lower lids, or both of them. An instrument can be used for dilating the tear duct opening to insert it more easily.
There are many punctal plugs that come prepackaged along with disposable devices for helping your eye doctor get the plug inserted.
There are inserters that are available in various designs, like forceps style that may squeeze to push a plug in place. Syringe-style, narrow inserts can also be used. Other instruments may be used by your eye doctor like forceps for help to put a punctal plug into the tear duct of your eye.
There are some punctal plugs that get inserted just inside the puncta so they are still able to be seen, and if necessary removed mechanically.
Other punctal plugs get inserted deep inside of the canaliculus, so they are not visible. Those kinds of tear duct plugs – which are technically referred to as intercanalicular plugs – don’t protrude out of the punctum. They conform automatically to the cavity’s shape and are not felt or seen.
In the rare cases where removal is necessary, intercanalicular plugs get extract through flushing them out.
Except for a bit of initial discomfort, after it has been put into place, you shouldn’t feel the punctal plug. Right after the procedure is over, you most likely will be able to drive home on our own and resume your regular activities.
Kinds of Punctal Plugs
There are many different shapes and designs of punctal plugs, including the following:
- Umbrella. This kind doesn’t “disappear” inside of the tear duct, which makes it easy to find and removed if needed.
- Tapered. With this type of design extra force is exerted horizontally in order to help keep a punctal plug in the right place.
- Hollow. Having a hollowed interior may help the punctal plug with adhering to the the shape of the tear duct of the eye.
- Reservoir. With this style, the tears are captured and held, which helps to increase comfort and reduce foreign body sensations.
- Low profile or slanted cap. With this design it can help with maintaining comfort and also provide some extra stability.
The materials that are using for making punctal plugs include hydrogel, polydiaxonone, hydrophobic acrylic polymer, collagen and silicone. There are some punctal plugs that get coated with a type of slick surface to make it easier to insert them.
Pliable, soft punctal plugs that are made out of common materials may increase the comfort level and help to more readily conform the device to the tear drainage channel’s shape.
There are currently two kinds of soft intracanalicular plugs that are available. One kind is made out of an acrylic material. At room temperature it is solid but on contact with the body’s heat melts. SmartPlug (Medennium)is an example of this, and it exists in a semisolid state similar to gelatin within the drainage channel.
Another kind of soft intracanalicular plug is made from hydrogel material that after it has been inserted inside of the lacrimal punctum, it then hydrates util the cavity is completely filled. One example of this kind of punctal plug is Form Fit (from Oasis Medical).
Old people especially may benefit from using soft punctal plugs since – with the aging process – orifices like tear drainage channel get larger and the muscular lining also gets less elastic. Softer punctal plugs in this case are more likely to remain in place compared to harder ones.
Problems And Side Effects Of Punctal Plugs
Punctal plug insertion is usually uneventful and very rarely involves problems or serious side effects.
Watery eyes and excessive tearing (epiphora) may occur whenever the punctal plug actually does too good of a job. When that happen, you might have to go see your eye doctor to have the plug removed or replace it with a different kind to control better how many tears are in your eyes.
Loss or displacement of the plug is fairly common and may happen for many different reasons, like when an individual rubs her or his eyes and dislodges the device accidentally. Hard kinds of punctal plugs especially are much more likely to get dislodged and then fall out. If that happens you will need to go see your eye doctor to get a replacement punctal plug.
Another potential problem that may occur with the devices is an eye infection, although they are rare. Canaliculitis is the result of a reaction to a punctal plug that is quite rare. Symptoms include swelling along with yellowish secretions coming from the tear ducts. These infections might result from an upper respiratory infection when blow one’s nose under pressure might force germs back from the nasal cavity into the canaliculus.
In those situations, you might need to be treated with oral antibiotics, topical antibiotics and/or have the punctum plug removed.
Another rare complication that might occur is when a plug migrates unexpectedly outside of the target area and deep inside of the drainage channels of the eye. That can create blockages that lead to conditions like dacryocystitis, that come with discomfort, pain and swelling.
Soft kinds of punctum plugs usually may be removed through flushing them out (referred to as irrigation). However, surgery may be necessary whenever a hard kind of punctum plug ends up migrating into the drainage canal of the eye. However, due to the current hard plug’s nail-shaped head, it is rare to have entrapment inside of the tear drainage canal.
With rigid kinds of punctum plugs, there is extra tissue formation that might happen as a reaction which causes the channel to narrow (referred to as stenosis). If needed, your eye doctor may take the punctal plug out. However, the purpose of the punctal plug is slowing down the exit of tears, therefore extra tissue may be beneficial since it helps with achieving this goal.
When Should You Have Punctal Plugs Removed
Although semi-permanent punctal plugs may last indefinitely, it is also easy to remove them.
If you feel any discomfort or think you might have an eye infection or another type of complication, then make sure that your eye doctor is notified.
If it is considered necessary to remove the punctal plug, then forceps might be used by your eye doctor to grasp the plug and extract it. Another removal method involves flushing it out using a saline solution. The punctal plug is forced to exit into the throat or nose where the tear ducts drain.