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What is A 60 year old man presented with watering from his left eye since 1 year. Syringing revealed a patent drainage system. Rest of the ocular examination was normal. A provisional diagnosis of lacrimal pump failure was made. Confirmations of the diagnosis would be by- and explain in detail?
Following tests are available for evaluation of epiphora:

For mechanical obstruction:-
	Regurgitation test, fluorescein dye test, lacrimal syringing test, Jones dye test, dacryocystography.
For functional (physiological) obstruction due to lacrimal pump failure:-
	Dacryoscintigraphy or radionucleotide dacryocystography (more sensitive), Fluorescein dye disappearance test.