The Pre-Sac Reflux Test (PSRT): a new diagnostic test for presaccal stenosis/obstruction

To introduce a new procedure, the Pre-Sac Reflux Test (PSRT), to screen for epiphora caused by presaccal stenosis/obstruction, and to determine the reliability of this new test in the diagnosis of presaccal stenosis/obstruction.

A nonrandomized, prospective, comparative case series of 280 eyes of 140 patients with unilateral presaccal stenosis/obstruction was performed. The PSRT was performed by a masked examiner on both eyes of each patient. After fluorescein staining, the lower lid was everted and lower punctum was observed using a cobalt-blue filter under slit-lamp magnification. After blotting excess fluorescein on the punbtum, the area of lacrimal ampulla was massaged with mild pressure with an index finger. The reflux (billowing of the fluorescein-stained tear) from each lower punctum were compared, and the bilateral symmetry was measured. In the same way, reflux from each upper punctum were compared for bilateral symmetry. The PSRT was considered positive if reflux from punctum was absent, or reduced asymmetrically, compared with that from contralateral punctum. If the test of either upper or lower punctum showed positive, the eye was considered positive. The validity of PSRT was measured by sensitivity and specificity, as well as positive- and negative-predictive values.

The PSRT used to diagnose presaccal stenosis/obstruction has a sensitivity of 92.9 % and a specificity of 97.1 %. It has a positive-predictive value of 97.0 % and a negative-predictive value of 93.2 %.

The PSRT is a reliable screening test for diagnosis of presaccal stenosis/obstruction.