<prompt> Dacrocytorhinostomy involves?Opening up the terminal blocked end of nasolacrimal ductConnecting the lacrimal sac to nose by breaking the medial wallComplete excision of lacrimalInseion of drainage tube in the lacrimal sac  <response>: Ans. is b i.e., Connecting the lacrimal sac to nose by breaking the medial wall Dacryocystorhinostomy is the surgical procedure which involves removal of bone adjacent to lacrimal sac medialwall and incorporating the lacrimal sac with lateral nasal mucosa at middle meatus in order to bypass the obstruction in nasolacrimal duct. Advantage of dacryocystorhinostomy over dacryocystectomy is that there is no epiphora or watering of eyes posteoperatively. Indications of dacryocystorhinostomy are :- Congenital or acquired nasolacrimal duct obstruction. Functional obstruction to lacrimal outflow e.g. lacrimal pump weakness or facial nerve palsy. History of dacryocystitis Dacryocystorhinostomy can be done either open external approach or endonasal endoscopic approach. 