2MacEwen C J, Young JD. Epiphora in the first year of life. Eye, 1991,5:596-600.
3Paul TO, Shepherd R. Congenital nasolacfimal duct obstruction: natural history and the timing of optimal intervention. J Pediatr Ophthalmol Strabismus, 1994,31:362-367.
4Lekskul A, Khamapirad B, Nimvorapun T. Simple technique for silicone intubation in congenital nasolacrimal duct obstruction. J Med Assoc Thai ,2004,87 : 1082-1086.
5Lim CS, Martin F, Beekenham T, et al. Nasolacrimal duct obstruction in children: outcome of intubation. J AAPOS,2004,8 :466-472.
6Kassif Y, Rehany U, David M, et al. The course of epiphora after failure of silicone intubation for congenital nasolacrimal duct obstruction. Graefes Arch Clin Exp Ophthalmol, 2005, 243: 758-762.