AS-OCT Reliably Detects Position, Patency of Lacrimal Punctal Plugs

close up head of young patient fix in Tomography in Optical Coherence
close up head of young patient fix in Tomography in Optical Coherence (OCT) equipment.
The prospective study also showed that the technology can detect tear meniscus height and area.

Anterior segment optical coherence tomography (AS-OCT) has the ability to detect proper positioning, patency, and contents of implanted perforated lacrimal punctal plugs, according to findings published in Eye and Vision. The technology also demonstrated use in measuring tear meniscus height (TMH) and tear meniscus area (TMA), according to the report. 

In a prospective study, researchers at the Minia University Hospital in Egypt used AS-OCT to evaluate the patency and position of perforated lacrimal plugs implanted for treating punctal stenosis. They also employed AS-OCTto quantitatively assess patients’ precorneal tear film. The lower punctums of 54 eyes (29 patients) were implanted with perforated punctal plugs, and were examined using AS-OCT during the early postoperative period. Researchers then postoperatively evaluated the patency of the plug, its position, TMH and TMA, and correlated the results with postoperative epiphora. For epiphora grading, Munk scale was used.

The AS-OCT technology found that 88.9% (n=48) of plugs were found in the proper position, while 11.1% (n=6) were rotated. In 87% (n=47) of plugs, the lumen was completely patent, in 3.7% (n=2), it was partially obstructed, and in 9.2% (n=5), the lumen was completely occluded. The postoperative decrease of TMH and TMA was statistically significant (P <.001), as was the postoperative epiphora Munk score (P <.001). 

The study explains that traditional slit lamp examinations are not capable of detecting the entire lumen, only the surface of the plug or the superficial part of its lumen, and that the plug appears patent in some cases when, in reality, the patent still has epiphora. The researchers explain that AS-OCT can show deeply seated plug obstruction, as well as even more specific features.

“AS-OCT imaging not only evaluated the patency, position, and even fine debris within the lumen of the plug in a very demonstrative manner but also the exact level of obstruction, whether partial or complete and the tear fluid level within the plug,” the study notes.

Moreover, the researchers note that, since deep plug occlusion can be managed by simply irrigating the plug for subsequent epiphora improvement, AS-OCT was reliable in this study in managing cases with postoperative epiphora despite proper plug position and clinically patent plug.


Abdallah RMA, Elshafei AMK, AttaAllah HR. Evaluation of implanted perforated lacrimal punctal plugs using anterior segment optical coherence tomography. Eye Vis (Lond). Published online October 3, 2021. doi:10.1186/s40662-021-00259-x