Voluntary blinking and use of 0.25% dye on fluorescein dye disappearance test.

To evaluate the effect of voluntary blinking and use of diluted fluorescein dye on fluorescein dye disappearance test (FDDT) in terms of diagnostic ability and test time.Prospective, nonrandomized case series.Thirty-nine patients who visited Hadong Seoul Eye Clinic between April 2009 and September 2009.All participants underwent FDDT and a lacrimal syringing test, and were divided into 2 groups according to the lacrimal syringing test results. FDDT was performed using 3 protocols: conventional FDDT (2% FDDT), FDDT with voluntary blinking (2% FDDTb), and FDDT with voluntary blinking using diluted fluorescein (0.25% FDDTb). The results were assessed by comparing initial tear meniscus height and those at 5 (2% FDDT) or 3 minutes (2% FDDTb, 0.25% FDDTb) after dye instillation. Results were considered "normal" when the tear meniscus decreased to less than 50% of its initial height, and "delayed" when it decreased to≥50%. In cases with a normal result, a half-period of dye disappearance was also recorded.Regarding diagnostic ability, the 0.25% FDDTb test had highest sensitivity and specificity among 3 protocols (100% and 80%, respectively). The half-period of dye disappearance was 3.17±1.72 minutes for 2% FDDT, 1.82±0.64 minutes for 2% FDDTb, and 1.04±0.69 minutes for 0.25% FDDTb, and showed significant difference among 3 tests (P = 0.001).The FDDT with voluntary blinking using 0.25% fluorescein had comparable diagnostic ability with the conventional FDDT, and allowed the test time to be significantly reduced.