A punctum plug, or punctal plug, is an implant that is inserted in the tear duct, or puncta, of the eye. It is intended to block the tear duct and is a treatment for dry eye. There are different forms of punctal plugs; some are temporary while others are more permanent. Often a temporary form of plug like collagen is inserted into the duct at first to see how the patient’s eyes respond before a more permanent solution is performed.
More permanent punctum plugs made from silicone and thermally reactive material. Some of these are inserted into the puncta as a liquid, while others start off as rigid and solid and become soft and pliable once implanted. This procedure has a very small risk to the patient and is not permanent. Most plugs last about 6 months before they are extruded from the eye.