Nasolacrimal Duct Obstruction

Abstract

Couch and White state in their recent report1Couch S.M. White W.L. Endoscopically assisted balloon dacryoplasty treatment of incomplete nasolacrimal duct obstruction.Ophthalmology. 2004; 111: 585-589Abstract Full Text Full Text PDF PubMed Scopus (32) Google Scholar that endoscopically assisted balloon dacryoplasty should be considered an appropriate treatment for some patients with incomplete nasolacrimal duct obstructions (NLDOs). However, in “Materials and Methods” the authors do not state how the investigator determined if a patient had an incomplete NLDO. A patient with a prolonged dye disappearance test, without other obvious causes of epiphora, and who is patent to lacrimal irrigation cannot be assumed to have an incomplete NLDO. If patients with these clinical findings are studied radiologically with dacryocystography and nuclear lacrimal scans, many are actually found to have tear stagnation with poor lacrimal pumping and poor outflow from the conjunctival sac. In these patients, tears do not reach the lacrimal sac. It is unclear why balloon dacryoplasty should be of any benefit in patients with tear stagnation.Second, besides undergoing balloon dacryoplasty, the patients studied were also treated with stent lacrimal intubation, systemic steroids, and topical steroids. It is unclear from the study what improvement, if any, the balloon dacryoplasty provided over these other treatments.Finally, the study did not contain a control group. The outcome was partly subjective, and the investigators were not blinded. Certainly, placebo and observer bias effects could account for much of the improvement identified.It would have been more interesting if patients were studied radiologically both before and after intervention to demonstrate any changes in their lacrimal function. A control group treated only with topical medication and/or with stent intubation would also be informative. Couch and White state in their recent report1Couch S.M. White W.L. Endoscopically assisted balloon dacryoplasty treatment of incomplete nasolacrimal duct obstruction.Ophthalmology. 2004; 111: 585-589Abstract Full Text Full Text PDF PubMed Scopus (32) Google Scholar that endoscopically assisted balloon dacryoplasty should be considered an appropriate treatment for some patients with incomplete nasolacrimal duct obstructions (NLDOs). However, in “Materials and Methods” the authors do not state how the investigator determined if a patient had an incomplete NLDO. A patient with a prolonged dye disappearance test, without other obvious causes of epiphora, and who is patent to lacrimal irrigation cannot be assumed to have an incomplete NLDO. If patients with these clinical findings are studied radiologically with dacryocystography and nuclear lacrimal scans, many are actually found to have tear stagnation with poor lacrimal pumping and poor outflow from the conjunctival sac. In these patients, tears do not reach the lacrimal sac. It is unclear why balloon dacryoplasty should be of any benefit in patients with tear stagnation. Second, besides undergoing balloon dacryoplasty, the patients studied were also treated with stent lacrimal intubation, systemic steroids, and topical steroids. It is unclear from the study what improvement, if any, the balloon dacryoplasty provided over these other treatments. Finally, the study did not contain a control group. The outcome was partly subjective, and the investigators were not blinded. Certainly, placebo and observer bias effects could account for much of the improvement identified. It would have been more interesting if patients were studied radiologically both before and after intervention to demonstrate any changes in their lacrimal function. A control group treated only with topical medication and/or with stent intubation would also be informative.