Punctal plug

A punctal plug, also known as tear duct plug or lacrimal plug, is a small medical device that is inserted into the tear duct (puncta) of an eye to block the duct. This prevents the drainage of liquid from the eye. They are used to treat .

Artificial tears are usually still required after punctal plug insertion.

A temporary punctal occlusion can be inserted and tried first. These are made of collagen and are dissolvable. This is to ascertain that permanent ones will not cause excessive tearing.

Permanent punctal plugs are usually made of silicone. These are available in various sizes. For maximum effectiveness, the largest size that fits should be used. These are more effective than collagen plugs. They can sometimes become loose and fall out, in which case they can be replaced.

Some plugs are made of thermally reactive material. Some of these are inserted into the punctum as a liquid, and then harden and conform to the individual's drainage system. Others start out rigid and become soft and flexible, adapting to the individual's punctal size after they are inserted.

The risks of punctal plugs are fairly small. There is a risk of eye irritation, excessive tearing, and, in rare cases, infection. Some doctors require a disclaimer to be signed prior to the insertion of a plug.

A large silicone plug can cause slight pain upon blinking after insertion. This discomfort may stop within a week.

A systematic review by the Cochrane Collaboration sought to assess the safety and efficacy of punctal plugs for the management of dry eye. The review included eighteen studies, testing punctal plugs of different materials, and comparing them to other treatments for dry eye. Overall there were mixed results; punctal plugs did not show consistent improvement of dry eye symptoms compared to the comparison group at follow-up. There was little evidence of differences between silicone and collagen or acrylic punctal plugs. Punctal plugs may be more effective than oral pilocarpine, but may be less effective than artificial tears. Some adverse outcomes from participants included spontaneous plug loss, epiphora, ocular irritation, foreign body sensation, and local inflammatory reaction.

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