Punctal plug insertion technique prevents intracanalicular plug migration

Although intracanalicular plug migration usually results in few adverse consequences, secondary complications may occur.

A new lacrimal punctal plug insertion technique was used in a study to successfully prevent intracanalicular plug migration during insertion.

Minako Kaido

The new technique produced no plug migration, study authors Minako Kaido, MD, and Murat Dogru, MD, PhD, said in an interview with Ocular Surgery News.

Intracanalicular plug migration, a complication associated with the conventional plug insertion technique, is asymptomatic and does not lead to adverse consequences in most patients. However, migration may lead to secondary complications, Dr. Dogru said.

“We never experienced any single incident of plug migration into the system,” he said. “This will probably avoid further complications related to migration or loss into the system such as granulation formation, secondary infection and so forth.”

Plugs lost in the lacrimal canalicular system may even continue to obstruct the system and improve dry eye symptoms, but complications may still arise.

“Sometimes, the plugs can be washed away — for instance, if you sneeze or cough — and you can lose the blocking effect, or sometimes they can cause granuloma formation,” Dr. Dogru said.

Trepidation about potential plug migration led to the new insertion technique.

“We were very nervous to proceed with lacrimal punctal insertion because we wanted to definitely avoid migration,” Dr. Kaido said. “So we were always thinking how we could avoid the migration. That is why I emphasized this new technique.”

The findings were published in the American Journal of Ophthalmology.

Patients and methods

The interventional, nonrandomized, comparative study included 45 dry eye patients who had a mean age of 52.7 years and underwent punctal plug insertion with the new technique and 33 patients who had a mean age of 50 years and underwent insertion with the conventional technique.

Overall, surgeons performed 120 procedures with the new technique and 132 procedures with the standard technique. All patients received SuperFlex Punctum Plugs (Eagle Vision) and underwent tear function examination and ocular surface examination.

Dry eye diagnoses were based on criteria of the Dry Eye Research Group in Japan. All patients underwent superior and inferior punctal occlusion and follow-up examination for at least 3 months.

The SuperFlex Punctum Plug is attached to the inserter with a built-in needle. The standard insertion technique involves a space between the plug and the inserter body.	In the insertion technique for SuperFlex Punctum Plugs devised by Minako Kaido, MD, and colleagues, the space between the plug and inserter body is eliminated by pressing the knob before insertion. Images: Minako K
The punctal ring rests on the inserter body when the space between the plug and inserter body is eliminated.	Even when the plug is inserted deeply below the punctal ring, it can be pulled up and removed to prevent plug migration.

Any candidate for punctal plug occlusion may safely undergo insertion with the new technique, Dr. Dogru said.

The SuperFlex plug inserter has a built-in L-shaped needle, with the longer section hooked to the plug inserter and the shorter section connected to the push button. Pushing the button moves the needle backward, making the plug body move toward the apex of the inserter body and detach for occlusion.

“It is our belief that when a space is present between the plug and the inserter … and when the plug is inserted beyond the lacrimal punctal ring, the ring moves toward the needle, forming a barrier to pull out a deeply inserted plug that predisposes the plug to intracanalicular plug migration,” the study authors said. “However, when the space between the plug and the inserter body is eliminated by pressing the knob before insertion, the punctal ring rests on the inserter body. Even when the plug is inserted deeply beneath the punctal ring, the plug still can be pulled up.”

Results and conclusions

The new plug insertion technique resulted in no incidents of intracanicular plug migration. Data showed 18 incidents of migration among the 132 standard insertion procedures (13.6%). The differences between the two techniques’ rates of intracanicular plug migration were statistically significant (P < .05).

Differences between the patient groups’ tear function and ocular surface staining scores were not statistically significant. Relationships between plug sizes and rates of intracanalicular plug migration also were not statistically significant.

Spontaneous plug loss was seen in 39.4% of eyes undergoing insertion with the conventional technique and in 30% of eyes undergoing insertion with the new technique. However, the difference between the two groups’ rates of spontaneous plug loss was not statistically significant.

“It should be remembered that the intracanalicular plug migration rate reported in this study is solely for the SuperFlex Punctum Plug, and that comparative future studies for other plugs will provide interesting information,” the study authors said. – by Matt Hasson

Reference:

• Kaido M, Ishida R, Dogru M, Tsubota K. A new punctal plug insertion technique to prevent intracanalicular plug migration. Am J Ophthalmol. 2009;147(1):178-182.

• Murat Dogru, MD, PhD, and Minako Kaido, MD, can be reached at Department of Ophthalmology, Keio University School of Medicine, Shinanomachi 25, Shinjuku-ku, Tokyo, Japan 160-8582; 81-03-3353-1211; e-mails: muratodooru@yahoo.com; fwiw1193@mb.infoweb.ne.jp.