If you suffer from Dry Eye Syndrome (DES), your ophthalmologist may recommend that you undergo a punctal occlusion. The lacrimal glands, found behind and above our upper eyelids, produce most of our tears. These tears enter our eye, forming the tear film. The film naturally drains out through the nasolacrimal duct, emptying in the nose. The entrance to this duct is the lacrimal punctum, which is a tiny opening you can find in the corner of your eye, on the eyelid. When you have DES, something in the entire tear production process goes wrong. You may not produce enough tears, or the quality of your tears may be poor. These are issues that can, at times, be resolved with a punctal occlusion.
What Is a Punctal Occlusion?
A punctal occlusion is procedure by which a small plug is inserted into puncta, slowing down how quickly tears are drained from the eyes. In so doing, they spend longer on your eye and this can help relieve the symptoms of DES, particularly if your condition is caused by insufficient tears. The procedure is performed on an outpatient basis.
The plug is made from collagen, which slowly dissolves in your eye. Some are now made of silicone, which doesn’t dissolve at all. They come in a range of different sizes as well. Nowadays, it is more likely that a permanent plug is inserted first. If you then find that your eyes start to water too much, the plugs will be replaced with dissolvable ones. Because they come in different sizes, your physician will usually start with a small one. If it falls out, they will move on to the next size up.
Punctal plugs are also called occluders or lacrimal plugs. They are around the size of a grain of rice. Usually, they will only be prescribed if you can show that eye drops, including prescription ones, have not resolved your DES.
DES is a very common side effect of having LASIK eye surgery. Hence, many clinics now insert dissolvable punctal plugs after the procedure. These will take several months to dissolve, by which time the eye should be fully healed.
Punctal Plug Insertion
Having something the size of a grain of rice inserted into the tiny hole in your eyelid sounds like a really scary thing. However, it isn’t all that bad. First, a physician will measure the size of the duct entrance, so that the right size plug can be found. This is done through a close up examination under bright lights. You will then receive some anesthetic, usually in the form of drops, although this is mainly to put your mind at ease, since the procedure doesn’t hurt. A special instrument then slightly dilates the duct, and the plug is simply inserted into place. Insertion is done through either a type of syringe, or through something that looks like a type of forceps. Once in position, you won’t be able to see or feel the plug.
It is very uncommon for a plug to have to be removed. However, if it is absolutely necessary, the plug will simply be flushed out.
The procedure (both insertion and removal) is quick and painless and does not require any recovery time. You can immediately resume normal activities, including driving.
Different Types of Punctal Plugs
The table below highlights the three possible punctal plug shapes.
|Umbrella||This is a type that stays slightly on top of the duct, meaning it can easily be removed.|
|Tapered||This stays solidly in place because extra force is exerted horizontally.|
|Hollow||These shapes are known to best adhered to the shape of the tear duct.|
|Reservoir||This type actually collects tears. They are known as the most comfortable, as some people do complain that they feel as if there is something in their eye for a while.|
|Low profile or slanted cap||This is a design that feels very comfortable, but is more stable than the hollow or tapered versions.|
The table below highlights some of the common materials in which punctal plugs. Sometimes, plugs are covered in a slick material, which helps to insert the device.
|Hydrophobic acrylic polymer||Solid at room temperature, but will melt when it warms up to body temperature.|
|Hydrogel||Hydrates on insertion, filling up the cavity.|
An ophthalmologist will be best able to decide which plugs are most suitable to the patient.
Problems and Side Effects
It is very rare for punctal plugs to have any negative side effects, other than a slight discomfort after having them had inserted. However, if the plug works too well, people may get watery eyes due to their tears no longer draining away. This is one of the rare occasions in which case the doctor may want to remove your plug, replacing it with a different type. If you had a dissolvable plug, however, it will usually simply be left to dissolve before a different type is tried.
A common problem is for the plug to become lost or displaced. There are a lot of reasons for this, but it is most commonly because people rub their eyes. This is particularly common in plugs made of harder materials. If this happens, you will need to go to your physician and have new plugs inserted.
Rarely, people will experience an eye infection as a result of having punctal plugs inserted. One infection is canaliculitis, which is a type of allergic reaction to the plug. You will experience yellow discharge and some swelling. Often, this is actually caused by having a type of cold or respiratory infection, which means pressure is placed on the canaliculus itself. If you have this infection, the plug may need to be removed and you will have to take antibiotic treatment.
It is also possible for the plug to migrate, entering the drainage channels of the eye itself. In this case, you may develop dacryocystitis, which is quite painful and uncomfortable, and will lead to swelling. If the plug was soft and dissolvable, it can usually be flushed out. With hard, permanent plugs, surgery will be required. It is very rare for this to happen, however, as most plugs are now tapered so that they cannot migrate.
Last but not least, it is possible that you will start to form extra tissue around the duct. This is a condition known as stenosis and means the channel becomes narrower. Most of the time, the plug is then simply removed. Once that is done, a lot of people feel like their DES is still alleviated because the narrowing of their tear ducts means that tears stay on the eye longer. A side effect with a benefit, in other words.
Situations in Which Punctal Plugs Have to Be Removed
All plugs can be removed, whether they are permanent or dissolvable. This may be necessary if:
- You feel very uncomfortable or the plug hurts.
- You develop an infection like canaliculitis.
- You develop dacryocystitis.
Other Things Punctal Plugs Are Use For
Punctal plugs have been designed to help alleviate the symptoms of DES. However, physicians are now considering whether they can also be used for drug delivery, and particularly for glaucoma medication. By using the plug, the medication can instantly disperse into the eye, which means no eye drops would be needed to treat glaucoma. With eye drops, a significant amount of the medication is lost as people blink it out, so this could be more effective, as well as cheaper.
Furthermore, punctal plugs may be able to control the pressure on the eye common with glaucoma, which leads to damage of the optic nerve and, eventually, vision loss. The Food and Drug Administration (FDA) is currently running clinical trials. They are also trying to determine whether it will make it easier for people to comply with the medication they have been prescribed, as it will let them avoid forgetting a dose of eye drops, for instance.
Resources and References:
A Stepwise Approach to Treating OSD – Punctal cautery for treaing ocular surface diseases. (Review of Ophthalmology)
Surgical Punctal Occlusion: A Prospective Study – Information on punctal occlusion. (NCBI)
Punctal Occlusion: Clinicians Encourage Its Use, Whether in the Upper Puncta – Recommendations of clinicians on the use of punctal occlusion. (Healio)
A Promising New Method for Administering Glaucoma Medication – Use of punctal plugs for delivering glaucoma medication. (Vision Aware)