If you or someone you know has been diagnosed with dry eye disease, you may have heard the term “punctal plug”. What is it and how does it work?
Dry Eye Disease
Punctal plugs are used as a treatment option for dry eye disease. Therefore, it is best to have a basic understanding of what dry eye disease is.
Dry eye disease can be a result of two things—either your tears evaporate too quickly (evaporative dry eye) or your eyes do not produce enough tears of the proper quality (aqueous deficient dry eye). You can also have a combination of the two types.
Regardless of the underlying etiology, dry eye disease can cause symptoms of irritation, intermittent blurry vision, itchiness, burning, grittiness, and believe it or not—excessive watering!
Whichever the cause of your dry eye, the issue is that there is not enough contact time between your tears and the front structure of the eye (cornea) containing an abundance of nerves.
When the tear quality is lacking, any kind of debris, air, temperature change, etc. can irritate the eye, resulting in the feeling of discomfort or overall dryness.
Treatment plans vary depending on the type of dry eye you have—some focus on helping the glands of the eyes to produce better quality tears whereas others focus on relieving the symptoms of the dryness with artificial tears.
Anatomy of the Tears
Believe it or not, the tears consist of 3 major layers—the anterior lipid layer, middle aqueous layer, and the posterior mucin layer.
The lipid layer is created mostly by meibomian glands within the eye lids.
The aqueous layer is produced by the lacrimal gland, which is located superior temporal to the eye—about where your outer upper eyebrow is.
The mucin layer is created by goblet cells within the eye’s outer conjunctiva.
The flow of tears, therefore, tends to enter the eye from the upper outside part, and travel down and inward toward the nose to lubricate the eye.
Within the eye lids, on the side closest to the nose, we all have a small drainage hole called the punctum.
There is a punctum located on both the upper and lower inner eyelids closest to the nose—thus we each have 4 in total.
After tears have become laden with debris, they flow out through the punctum, through a channel called the canaliculus, into the lacrimal sac (located close to the base of the nose), and then into the nasolacrimal duct where it combines with the unwanted nasal secretions and is eventually either reabsorbed by the body or excreted.
Since one of the main problems of dry eye disease is the fact that the “good” tears are not making long enough contact with the cornea, one treatment option is to “close the drain” to force the tears to remain on the surface of the eye.
Punctal plugs do just that! They are inserted into one (or more depending on the severity) of your punctas and block the drainage of tears into the canaliculi. This keeps the tears on the surface of the eye for longer periods of time and reduces symptoms of dryness.
Punctal plugs can be made of silicone or collagen. The silicone ones stay in for longer periods of time (some can stay in for many years before needing to be replaced!) whereas the collagen ones dissolve after a few weeks.
When inserting punctal plugs, your eye doctor will take a close look at your eyelids and punctas with a special tool called a slit lamp.
A slit lamp is essentially a microscope that magnifies your eyes so that your doctor can look at them close up. Through careful observation, your doctor will be able to choose the right size plug for your puncta.
Next, your doctor will numb the eye topically using eye drops to ensure the procedure will not hurt. He or she will then use a tool called a dilator to expand your puncta for easier insertion of the plug. Lastly, the doctor will use a special pair of sterilized tweezers to gently insert the plug into your puncta, tapping it in so that it is flush with the outer punctum.
After one last careful examination of the lids, you will be good to go! The entire process takes less than 20 minutes to complete and you will be on your way to more comfortable vision.
Generally speaking, punctal plugs do not need to be removed. The collagen ones self-dissolve with time, and the silicone ones typically remain in until they fall out on their own many years down the road.
If you suspect you have an eye infection or are feeling great discomfort, contact your eye doctor and he or she may choose to remove the plugs in office.