Endoscopic Evaluation of Lacrimal Mucosa With Indigo Carmine Stain

Use of indigo carmine dye as an in vivo adjunct in lacrimal microendoscopy is useful for accurately detecting areas of highly damaged lacrimal mucosa. Purpose: Histological investigation in the use of indigo carmine for detection of mucosal pathology in lacrimal microendoscopy. To investigate the histopathological correlation of staining found on lacrimal microendoscopy. Methods: A prospective case series was conducted in patients with a history of nasolacrimal duct obstruction and dacryocystitis requiring treatment with dacryocystorhinostomy or dacryocystectomy. Prior to lacrimal surgery, all patients underwent endolacrimal evaluation using transpunctal lacrimal microendoscopy. Indigo carmine dye (0.2 mg/0.5 ml) was injected into the lacrimal system via the irrigation channel of the endoscope, and after copious irrigation, the differential mucosal staining was recorded. Histopathologic analysis of tissue samples of positively and negatively stained lacrimal sac mucosa collected after surgery was performed to investigate the correlation with the results of each endoscopic evaluation. Results: Four patients underwent dacryocystorhinostomy and 2 patients underwent dacryocystectomy. Histopathology of positive-stained lacrimal sac mucosa corresponded to areas of the advanced fibrous stage of mucosal changes resulting from dacryocystitis, which showed atrophy of epithelium associated with the loss of goblet cells and subepithelium fibrous scarring. In contrast, areas of lacrimal mucosa that did not stain with indigo carmine were still in an active inflammatory stage of dacryocystitis preserving columnar epithelium with goblet cells. Conclusions: This study suggests that indigo carmine staining is a useful adjunct in lacrimal microendoscopy for accurately detecting areas of highly damaged fibrous lacrimal mucosa, as it allows for direct visualization of lacrimal mucosal pathology and can provide prognostic insight and guidance in regard to treatment options for patients with lacrimal drainage obstruction.