Punctal Occlusion (Punctum Plugs) for Dry Eyes

One of the causes of dry eyes discussed in the section entitled "Red, Dry Eyes" is when a person doesn't produce enough water in their tears. Tears are produced by the Lacrimal gland, a gland that rests superiorly behind the temporal bone of the orbit of the eye. The tears "drip" towards the surface of the eye, and the blink pushes them temporally across the surface of the eye. In the nasal part of the eye there are two ducts, one within the lower nasal corner of the eyelid and one within the upper nasal corner. These ducts are called Punctum, and tears drain out of the eye through these punctum. If you look closely in a mirror and pull your lower eyelid down, you can actually see the little dark hole. The theory behind punctal occlusion is just that - occlude the punctum; not as many tears will drain out of the eye, keeping it more moist. If you think of this system as a sink and faucet mechanism, the Lacrimal gland is the faucet, the eye surface is the basin and the punctum are like having two drains within the basin. If you clog one drain, the fluid doesn't drain out as fast and stays around longer to keep the basin wet.

Punctal occlusion is often successful in treating the symptoms of dry eyes. Responsible fitting of a punctal plug involves several steps by your eye doctor. First, the cause of your dry eyes must be evaluated. If your dry eyes are not the result of low tear layer, decreased tear production or excessive tear drainage, punctal occlusion may not help. If your doctor finds that any of these three problems exist, the doctor will perform a series of quick tests to determine the extent of the dry eye. The tests the doctor may perform prior to inserting plugs include the Schirmer Test, the Tear-Break-Up-Time test and/or the Phenol-Red Thread test. Most of these tests use absorption means to determine how much fluid is available as a unit of time. They may also stain your eye with Lissamine Green dye or Rose Bengal red dye to rule out other problems or conditions prior to proceeding with the plugs. Most of these dyes are vital dyes that stain dead and dying cells. If staining occurs, the doctor can use that information to determine how dry the eye is.

The doctor will start by using a tiny, tube shaped, opaque collagen implant. Collagen implants absorb fluid and swell within the punta, clogging it up. They dissolve in 4-7 days. The reason a temporary implant is used is because they are less expensive than permanent implants. If there is no relief during the 4-7 days of wear, permanent plugs probably won't help, and the trial will be over at less expense to the patient. But if there is even the slightest bit of improvement in dry eye symptoms with the temporary collagen implants, the permanent plugs will work 2-3 times better and they will be worth trying.

Holding the implant in a tweezer, and using a high-powered magnification device called a slit-lamp, the doctor will line the plug up with the punctum and push the bottom part of the plug 1/3 to ½ of the length of the plug into the hole. The doctor will then use the tweezer to push down on the top of the cylinder so the remainder of the plug disappears beneath the lid surface. If a plug irritates the eye, it may be caused by the plug not being fully inserted beneath the eyelid and the plug may rub the surface of the eye. Symptoms of dryness may still be present for up to 2 days after the plug is installed, but between 2-4 days the patient may feel relief.

When the patient returns for the 1week follow up, the doctor will ask if there is any subjective improvement in their dry eye symptoms. If the patient answers in the affirmative, the doctor will discuss the use of a permanent silicon implant. Note, a permanent silicon implant does not mean it can't be removed, it only means it won't melt away. A permanent silicon implant usually can easily be removed if the patient so desires. Should the patient agree, the installation of the permanent plug may begin. Most permanent plus have a parachute-shape - a pointy lower portion to guide the plug into the hole of the puncta. The top part of most plugs has a flat portion, kind of like an anchor, so the plug won't go totally beneath the surface of the puncta and can be easily manipulated if necessary. Unlike the harder collagen plug, the silicon plug is soft, so a small part of it can remain outside of the hole and, in most cases, the eye won't notice it's there. Nobody will be able to see the plug looking at you, because it is small and clear, and you may even have a hard time seeing it. The installation of the permanent plug is slightly more difficult for the doctor, as it is larger than the collagen plug, so you may feel some slight pressure and even a quick, sharp pinch as the doctor pushes the plug into the small puncta. This is not surgery - your eyelid is not compromised and there is no blood-letting. Nothing is cut either.

One week after insertion, the doctor will want to see you back at the office to see if your symptoms have resolved. The doctor will also look to see if the plug stayed in the hole. If it fell out, the doctor may decide to try a larger plug that will fit more snuggly. You may try to look in a mirror to determine if the plug is still there, but they are hard to see. If one eye starts to suddenly feel dry again, you may have one plug that fell out, and you should follow up with your doctor.