What is the most likely reason for a patient experiencing excessive tearing after a positive Jones I dye test?

In the context of excessive tearing (epiphora) and a positive Jones I dye test, the most likely reason is hypersecretion of tears. The Jones I dye test is used to assess the patency of the nasolacrimal duct. A positive result typically indicates that dye has reached the nasopharynx, suggesting that the duct is open; thus, obstruction is less likely.

When excessive tearing is observed in a patient with a positive test, it often indicates that tear production exceeds normal rates rather than the inability of tears to drain properly. Hypersecretion can occur due to a variety of reasons, including ocular surface irritation, inflammatory conditions such as dry eye syndrome, or reflex tearing due to environmental factors. The excess tears produced ultimately lead to overflow.

Understanding this mechanism highlights that the issue is related not to the drainage system itself but to an overproduction of tears, which explains the excessive tearing despite a functional drainage pathway.