Acquired nasolacrimal duct obstruction is a side effect of therapy of which of the following medication

Ans. a. Timolol Acquired nasolacrimal duct obstruction is a side effect of chronic use of timolol-containing topical glaucoma therapy. "Chronic use of timolol-containing topical glaucoma therapy preparations in glaucoma patients is associated with an increased risk for the development of nasolacrimal duct obstruction (NLD0)."- Seider N, Miller B. Beiran I. Topical glaucoma therapy as a risk factor for nasolacrimal duct obstruction.