The Result of Byon's Test in Incomplete Nasolacrimal Duct Obstruction

ABSTRACT

PURPOSE: To assess the threshold of draining capacity, we performed Byon's test in patients complaining epiphora with incomplete nasolacrimal duct obstruction. METHODS: We measured the draining capacity by using Mclntyre R cannula in 54 patients (98 eyes) from February to December 2000. Through the cannula inserted to lacrimal sac we instilled distilled water for 1 minute at the height of 1.3 meter, then we counted the amount of fluid dropped. RESULTS: The mean values of draining capacity were 2.42+/-0.92 cc/min in men, 2.20+/-0.90 cc/min in women (2.25+/-0.91 cc/min in total). These were lower than normal value by about 48% and the difference was statistically significant (P<0.0001). The highest values in each group were 3.53 cc/min in men, 3.45cc/min in women. Epiphora developed when the draining capacity decreased under the 79% of normal capacity. CONCLUSIONS: This study supports the previous theory that incomplete nasolacrimal duct obstruction may progress to complete obstruction. We hope for another convenient and accurate method for quantitative measurement of lacrimal drainage capacity which will be positioned as a basic test of ophthalmology.