Restenosis After Lacrimal Stent Intubation in a Patient With Indigo Carmine Positivity: A Case Report.

Nasolacrimal duct obstruction (NLDO) is commonly treated with lacrimal stent intubation, yet restenosis remains a frequent challenge. Indigo carmine staining has been reported in research settings as an adjunct in dacryoendoscopy for evaluating mucosal integrity, mainly after tube removal. However, its clinical application has not yet been established, and there are no reports of routine use in daily practice. We present the case of a 55-year-old woman who presented with epiphora, discharge, and itching of the left eye, with a history of lacrimal intubation 10 years earlier. At our clinic, dacryoendoscopy revealed right common canalicular obstruction and left NLDO with clinical features consistent with chronic dacryocystitis, for which bilateral lacrimal intubation was performed. Eight weeks later, the tubes were removed, and dacryoendoscopy was repeated. Indigo carmine (2 mg/0.5 mL) instillation revealed focal staining of the left nasolacrimal mucosa, consistent with localized fibrosis. Six weeks after tube removal, restenosis developed in the left lacrimal drainage system, and the patient was referred to another hospital for dacryocystorhinostomy. This case highlights the potential of indigo carmine staining, performed after lacrimal intubation, in detecting fibrotic mucosa at risk of restenosis. Although promising, its clinical use has not yet been implemented, and further studies are required to establish its prognostic role in NLDO management.