Research into in vivo morphology of canalicular/lacrimal sac mucosal folds (CLS-MFs) uncovered a wide variation of location and extent along the internal canalicular orifice (ICO), according to investigators. They may even be responsible for the phenomena of false soft stops observed in preoperative syringing cases in endoscopic exams, according to study results published in Ophthalmic Plastic and Reconstructive Surgery.
Researchers suggest that CLS-MFs may have a role in the pathogenesis of lacrimal sac mucocele and acute dacryocystitis and create a false soft stop observed on probing a mucocele or dacryocystocele in the lacrimal drainage system. Prior studies, using cadavers, had limitations due to possible tissue shrinkage or maceration. The objective of this study was to evaluate the in vivo morphology of CLS-MFs during endoscopic dacryocystorhinostomy while also searching for the relationship between the presence of folds and preoperative probing findings.
In this study, researchers analyzed details of CLS-MFs folds, probing findings, and outcomes of dacryocystorhinostomy during endoscopic exams of the ICO in 34 patients undergoing endoscopic dacryocystorhinostomy between September 2018 and May 2019 at 2 tertiary eye care referral institutes. A total of 36 lacrimal systems were examined.
Researchers revealed that 100% of the 36 lacrimal systems had a single common canalicular orifice entering the lacrimal sac. Visible CLS-MFs were observed in 22 lacrimal systems (61.1%), 3 of which were overhanging the ICO and required manipulation of the probe to enter the lacrimal sac. No 2 types of CLS-MFs were observed in any 1 case. Excision was required for one lacrimal system that had a true membrane overlying the ICO, and no correlation was observed between the type of folds and age/sex (P >.05). One lacrimal system had lacrimal sac mucocele with CLS-MFs located along the posterosuperior edge extending for 270° that led to a soft stop preoperatively at 9 mm. All patients had successful dacryocystorhinostomy outcomes.
The study researchers concluded that CLS-MFs vary in terms of morphological location, presence, and extent along the ICO, and may be causing the false soft stop observed in cases on preoperative syringing, but do not need to be excised.
Singh S, Curragh DS, Davis G, Selva D. In vivo morphological study of common canalicular orifice and its impact on lacrimal probing. Ophthalmic Plast Reconstr Surg. 2020;36(4):410-413.