Fluorescein-tear breakup time as an assessment of efficacy of tear replacement therapy in dry eye patients: a systematic review and meta-analysis

Purpose: To review outcomes of studies where fluorescein-tear breakup time (fTBUT) measurements had been made before and after treatment with artificial tears. Methods: Peer-reviewed articles were identified that reported average values for fTBUT before and after approximately 1 month of treatment of dry eye with aqueous-based artificial tears. 48 data sets were used for calculating the net (percentage) change in fTBUT, with 21 including information of variability (as reported SD of average value) of the fTBUT data suitable for a meta-analysis. Results: Prior to treatment, average fTBUT values ranged from 0.9 s to 11.8 s (group mean 4.7 +/- 1.7 s, n = 48 data sets). After treatment, these values ranged from 2.2 to 10.7 s (group mean 6.1 +/- 2.3 s; P < .001), with net increase for the treatment effect being 1.4 +/- 1.2 s (range - 1.4 to + 4.5 s). Similar changes were reported regardless of the type of product type. The metaanalysis confirmed a net effect at 1.3 s, with the magnitude of the variability (as a weighted SE) having a similar overall value of 1.1 s. Conclusions: Following use of 'artificial tears' by dry eye patients, a small but predictable increase in tear film stability has generally been reported, the net magnitude of which is close to a 33% improvement.