Adult nasolacrimal duct bypass tubes: where do they go?

A 47-year-old man presented with a 1 year history of left epiphora. Six years previously it had been treated surgically in Turkey, although surgical details were not available and no external scars were evident. His vision was Snellen 6/6 right and 6/60 left, the decreased left acuity being a result of past stromal herpetic keratitis. All four puncta were patent and the right lacrimal drainage system was open to irrigation. Syringing of the left lower canaliculus resulted in fluid reflux through the upper.