Novel Evidence Concerning Lacrimal Sac Movement Using Ultra-High-Frequency Ultrasound Examinations of Lacrimal Drainage Systems

Orbital Septum Posterior to Medial Canthal Tendon Area

PURPOSE

To examine the anatomy of the orbital septum posterior to the medial canthal tendon area.

MATERIALS AND METHODS

We performed 3 anatomical dissections in the present study. The first one was a microscopic study in which exenterated specimens from 6 Japanese cadavers (age from 77 to 93 years at death) were cut inferno-horizontally, including the Müller muscle, medial rectus pulley, and lateral rectus pulley, and stained with Masson's trichrome. The second one was also a microscopic study in which the exenterated specimens from 5 Japanese cadavers (age from 73 to 87 years at death) were cut horizontally, 1 mm superior to the upper eyelid margin and 1 mm inferior to the lower eyelid margin, and stained with Masson's trichrome. The third one was a macroscopic study in which exenterated specimens from 5 Japanese cadavers (age from 73 to 91 years at death) were cut horizontally at the medial palpebral commissure.

RESULTS

In the first study, all the specimens showed the orbital septa with close vicinity to the orbicularis oculi muscle in the medial area. The second and third studies both demonstrated the double lamellar structure of the medial canthal tendon area. The anterior one was the fibrous tissue corresponding to the white medial canthal tendon. The posterior one referred to the preseptal orbicularis oculi muscle. The orbital septum was located directly posterior to this muscular structure.

CONCLUSION

The orbital septum posteriorly lined the preseptal orbicularis oculi muscle, the muscular part of the medial canthal tendon.

Lacrimal Sac, Classified within the Orbital Tissue

PURPOSE

To disclose that the lacrimal sac is classified within the orbital tissue.

MATERIALS AND METHODS

Ten orbits of 9 Japanese cadavers aged 64 to 85 years at death were included. The attachment site of the orbital septum in the medial canthal area was grossly dissected. The relationship between the orbital septum attachment site and the location of the lacrimal sac was examined.

RESULTS

In the upper region, the orbital septum was attached to the most superior area of the lacrimal fossa and the medial canthal tendon. In the lower region, the septum was attached to the anterior lacrimal crest and the medial canthal tendon. In both the upper and lower regions, none of the septa attached to the posterior lacrimal crest. The lacrimal sac was situated behind the orbital septum.

CONCLUSION

The lacrimal sac, which is situated behind the orbital septum, is classified within the orbital tissue.

UHFUS: A Valuable Tool in Evaluating Exocrine Gland Abnormalities in Sjögren's Disease

Sjögren's Disease (SjD) is a chronic autoimmune disorder that affects the salivary and lacrimal glands, leading to xerostomia and xerophthalmia. Ultrasonography of Major Salivary Glands (SGUS) is a well-established tool for the identification of the salivary glands' abnormalities in SjD. Recently, a growing interest has arisen in the assessment of the other exocrine glands with ultrasonography: lacrimal glands (LGUS) and labial salivary glands (LSGUS). The objective of this study is to explore the practical applications of ultra-high frequency ultrasound (UHFUS) in the assessment of lacrimal glands and labial salivary glands. Indeed, UHFUS, with its improved spatial resolution compared to conventional ultrasonography, allows for the evaluation of microscopic structures and has been successfully applied in various medical fields. In lacrimal glands, conventional high-frequency ultrasound (HFUS) can detect characteristic inflammatory changes, atrophic alterations, blood flow patterns, and neoplastic lesions associated with SjD. However, sometimes it is challenging to identify lacrimal glands characteristics, thus making UHFUS a promising tool. Regarding labial salivary glands, limited research is available with conventional HFUS, but UHFUS proves to be a good tool to evaluate glandular inhomogeneity and to guide labial salivary glands biopsy. The comprehensive understanding of organ involvement facilitated by UHFUS may significantly improve the management of SjD patients.

Clinical application of ultra-high frequency ultrasound: Discovering a new imaging frontier

The ultra-high frequency ultrasound (UHFUS) is characterized by the use of probes between 30 and 100 MHz. This technology has recently been introduced in clinical practice and represents an opportunity for the diagnosis of numerous pathologies. The high spatial resolution of UHFUS, up to 30 μ in pixel size, allows to study the pathological modifications and to guide microsurgery treatments in anatomical body structures not evaluable by conventional HFUS. The aim of this work is to provide a review of the literature on the current clinical applications of UHFUS and to discuss its added role in different clinical settings.