Govindram Seksaria Institute of Dacryology, L.V. Prasad Eye Institute, Hyderabad, India.
Ophthalmic Plast Reconstr Surg. 2019 Nov/Dec;35(6):628-630. doi: 10.1097/IOP.0000000000001467.
The aim of this study was to examine the ultrastructural features of the canalicular entrance into the lacrimal sac.
Ten openings of the common canaliculus into the lacrimal sac from 10 lacrimal sacs obtained during a dacryocystectomy were studied. Each of the openings were completely excised with 3-4 mm margins on all sides and transported to the laboratory in 2.5% glutaraldehyde. The analysis was performed using the standard protocols of scanning electron microscopy (SEM). The openings, their edges, canalicular lacrimal sac-mucosal folds, and internal surfaces were studied.
Of the 10 common canalicular openings studied, the upper and lower canaliculi opened into a common canaliculus in all the cases. The terminal portion of the 2 canaliculi had a common wall, which appeared like a septum, just proximal to the beginning of the dilated common canalicular portion. In 60% (6/10) of the cases, a diverticular or a type III sinus of Maier (SOM) was noted. The surface of this diverticulum was smooth and lined by stratified columnar epithelium, reflecting its lacrimal sac origins. Interestingly, the junction of the epithelial change from stratified squamous to columnar could be appreciated clearly in 80% (8/10) of the cases and was mostly located just within from the edge of the internal common opening (ICO). The canalicular lacrimal sac-mucosal folds could be appreciated in 70% (7/10) samples, being very defined and prominent in 30% (3/10).
The common merged wall of the 2 canaliculus is the most proximal and prominent structure noted on an end-on view of the ICO. Diverticular variant of the sinus of Maier is common. The junction of the epithelial change from stratified squamous to columnar is appreciated just within the edge of the ICO.Detailed anatomical features of the common canalicular opening into the lacrimal sac can help our understanding of the focal anatomy and tear rheology.
本研究旨在探讨泪小管进入泪囊的管腔入口的超微结构特征。
对 10 例泪囊切除术中的 10 个共同泪小管进入泪囊的开口进行研究。每个开口均用 3-4mm 边缘完全切除，并在 2.5%戊二醛中运送到实验室。分析采用扫描电子显微镜（SEM）的标准规程进行。研究了开口及其边缘、泪小管-泪囊黏膜皱襞和内表面。
在研究的 10 个共同泪小管开口中，上、下泪小管均在所有病例中开口于共同泪小管。2 个小管的终末部分有一个共同壁，该壁在扩张的共同泪小管部分开始的近端处类似于隔膜。在 60%（6/10）的病例中，注意到憩室或 Maier（SOM）第三型窦。该憩室的表面光滑，衬有复层柱状上皮，反映了其起源于泪囊。有趣的是，在 80%（8/10）的病例中，可以清楚地看到上皮从复层鳞状变为柱状的交界处，并且大多数位于内共同开口（ICO）边缘内。在 70%（7/10）的样本中可以观察到泪小管-泪囊黏膜皱襞，其中 30%（3/10）非常明显。
在 ICO 的端视图上，最靠近且最突出的结构是 2 个小管的共同融合壁。Maier 窦的憩室变体很常见。从复层鳞状上皮到柱状上皮的上皮变化交界处位于 ICO 边缘内。共同泪小管进入泪囊的详细解剖特征有助于我们了解焦点解剖和泪液流变性。
