Figure 1 – This cartoon illustrates the pathways of tear drainage out of the eyes. Generally, the lower puncta is plugged first because most tears are lost downwards in the direction of gravity.
Punctal plugs are small medical devices that sit in the drainage holes of the lids (called “puncta”). There is a puncta in the upper and lower lid. The two puncta drain into a channel that connects both the upper and lower passages before continuing on, allowing tears to drain down the back of the throat (see Figure 1). These small, easily-inserted plugs prevent tears from draining down the tear passage that they plug. Punctal plugs are a great method of treating some forms of dry eye.
Figure 2 – Tears drain via the upper puncta, lower puncta, and via evaporation.
There are many different types of dry eye, and for those patients suffering from a lack of tear volume, punctal plugs may be an excellent, long-term solution to preventing symptoms including red eye, sandy/gritty-feeling eyes, and even blurred vision which often accompanies a chronically dry eye. Tears drain via three different ways out of the eyes (see Figure 2). Tears can drain through the upper puncta, lower puncta, and by means of evaporation. The upper puncta drains less tears than the lower puncta, as gravity tends to draw more tears towards the ground. Evaporation can be curbed with goggles in extreme dry eye cases, but such treatment generally isn’t practical for most patients.
Figure 3 – This image illustrates the difference in shape between a silicone punctal plug (left), and a collagen plug (right).
Punctal plugs are used to treat chronic dryness after other methods of dry eye therapy have failed. Other methods of dry eye treatment include artificial tear regimens, ointments, and fish oil supplementation. There are two general types of punctal plug (see Figure 3). The first type is a collagen plug. Collagen plugs are designed to only last for about 10 days before dissolving. Our optometrists will use collagen plugs to explore if a patient has a positive reaction to puncta plugs before investing in a more
Figure 4 – This shows how a silicone punctal plug stays in place. Note how the shape of the plug both allows for the plug to stay in place, as well as to create a smooth, comfortable surface at the entrance to the puncta.
permanent solution. Collagen plugs are also sometimes utilized in our LASIK patients, as dryness is often at its worst immediately following surgery. The second type of plug is made of a soft silicone. Silicone plugs fit snugly in the puncta (see Figure 4) and anchor themselves in place due to their shape (sometimes likened to an upside down umbrella). Silicone plugs sit flush against the lid and comfortably prevent tears from draining. Silicone plugs are considered permanent in that they will not dissolve, but removable in that our doctors can remove a plug if the eyes end up being too watery or the plugs become irritating (which is not common).
Punctal plugs may be a great option for patients suffering from dry eye. Please ask our optometrists if you would be a good candidate for this procedure, or call us at (303) 450-2020 to schedule your next eye exam.
