Assessment of functional nasolacrimal duct obstruction--a survey of ophthalmologists in the southwest.

The term 'functional nasolacrimal duct obstruction' describes patients with epiphora where the tear duct is partially or completely patent to syringing. Delayed tear drainage is demonstrated with a fluorescein dye disappearance test (FDDT) or lacrimal scintigraphy. A dacrocystogram is also frequently abnormal. Studies show that selected patients with epiphora because of functional nasolacrimal duct obstruction have an 80-90% success rate with open or endonasal dacryocystorhinostomy. To find out if such patients were being considered for surgery, we sent a questionnaire to all ophthalmologists in the southwest. Of the 198 questionnaires, 163 were completed and returned (82%). In the assessment of epiphora, fewer than half those questioned (41%) regularly used an FDDT and only 51% syringe patients themselves. Most did not use lacrimal scintigraphy or dacrocystography if the drainage system was patent on syringing. This survey shows that many patients with epiphora who are patent to syringing are being incompletely assessed, and hence not considered for dacrocystorhinostomy. We recommend that an FDDT is performed on all patients, syringing is carried out by experienced staff, and more radiological investigations are undertaken, so patients with a highly treatable cause of epiphora can be offered dacrocystorhinostomy.