Comparison of fluorescein break-up time measurement reproducibility using standard fluorescein strips versus the Dry Eye Test (DET) method

Purpose. To compare the repeatability of fluorescein break-up time (FBUT) measurements determined with either a standard fluorescein strip or the Dry Eye Test (DET) modified fluorescein strip methods. Methods. This was a prospective, randomized contralateral study of 100 patients, in which FBUT measurements were determined with a standard FUL-GLO fluorescein strip (Akorn, Inc., Buffalo Grove, IL, U.S.A.) in one eye and a DET strip (Akorn, Inc., Buffalo Grove, IL, U.S.A.) for the contralateral. eye. Three consecutive measurements were made immediately after fluorescein instillation. The second eye was evaluated I minute after completion of the first eye. Data from patients with FBUT values less than 20 seconds were included in the data analysis, because measurements greater than 20 seconds are not diagnostically significant. Results. Seventy-five patients met enrollment and FBUT measurement criteria. For three consecutive FBUT measurements, the DET values were within 3 seconds for 72 of the 75 patients (96%). Eighty percent of patients reported no sensation with the DET strip, 20% reported mild sensation, and no patient reported moderate sensation. With FUL-GLO strips, measurements were within 3 seconds for 53 of the 75 patients (71%) (p <0.005). The standard fluorescein strip method elicited reports of no sensation from 31% of patients, mild sensation from 60%, and moderate sensation from 9% (p <0.001). Conclusions. The DET strip provides a significant reduction in sensation upon application, improved single measurement reliability, and enhanced measurement precision, compared with a conventional fluorescein strip.